Academic literature on the topic 'Temperate fish species'

The peripheral oculomotor system can be modelled as a first order linear system (Montgomery, 1983), and hence specified by its characteristic frequency and ‘d.c.’ gain. These parameters can be determined by recording eye movements produced by stimulation of the abducens nerve with sinusoidally modulated pulse trains, and compare well with those independently derived from the relationship between motoneurone firing and spontaneous eye movement. Characteristic frequency and gain of the peripheral oculomotor system were determined for two species of antarctic teleost and one temperate species, to examine temperature compensation within a complete motor output pathway. Compared with low temperature function in temperate fish, the characteristic frequency is clearly temperature compensated in antarctic fish, which explains in part the observed temperature compensation of their rapid eye movement. The ‘d.c.’ gain of the peripheral oculomotor system is inversely related to temperature, providing an automatic compensation for possible reductions in central nervous system output and sensory gain at low temperature.

The theory of maximum sustainable yield (MSY) underpins many fishery management regimes and is applied principally as a single species concept. Using a simple dynamic biomass production model we show that MSY can be identified from a long time series of multi-stock data at a regional scale in the presence of species interactions and environmental change. It suggests that MSY is robust and calculable in a multispecies environment, offering a realistic reference point for fishery management. Furthermore, the demonstration of the existence of MSY shows that it is more than a purely theoretical concept. There has been an improvement in the status of stocks in the Northeast Atlantic, but our analysis suggests further reductions in fishing effort would improve long-term yields.

Several species interrelationships influenced by actural or preceived disturbances were described which managers should consider when manipulating fish populations and communities. For example, factors controlling homeostasis of adult northern pike (Esox lucius) and white suckers (Catostomus commersoni) in northern lakes may still operate despite walleye reductions, suggesting less niche overlap than we previously expected. In more northern centrarchid type communities, percid abundance and condition depend on how well northern pike and other predators control both white sucker and bluegill (Lepomis macrochirus) abundance. Evidence from walleye (Stizostedion vitreum vitreum) fry and fingerling plantings suggest that when intense interactions between species determine their abundance, these interactions occur during the very early life stages. Climatic changes may also be influential in determining abundance of several fish species common in north-temperate lakes. Rehabilitation of preferred species by removal of less desirable fishes can be successful in some ecosystems, but we warn that an undesirable compensatory response may also occur.

Mangroves are considered to support rich assemblages of fish and invertebrates. Fishes inhabiting mangrove habitats and at various distances from mangroves across mudflats were sampled to: (1) compare fish assemblages between habitats; and (2) determine the influence of mangrove proximity on fish abundance and diversity in three southern Australian estuaries between November 2005 and January 2006. Based on their distribution, fish species were classified as mangrove residents, mudflat residents, generalists or rare species. The assemblage structure of fish in mangroves differed from assemblages 500 m away; however, neither total abundance nor species richness differed significantly between mangroves and mudflats. Mangrove residents and Aldrichetta forsteri (yellow-eyed mullet) displayed strong associations with mangrove habitats, whereas mudflat residents were associated with mudflat habitats. No other fish groups or individual species occurred in higher abundances in either habitat. Total fish abundance, mangrove residents and A. forsteri were positively correlated with pneumatophore density, indicating that the structural complexity of the mangroves might influence the distributions of certain fish species. The current study demonstrated that mangrove habitats in temperate Australia support no greater abundance or diversity of fish than adjacent mudflat habitats and that mangrove proximity does not influence fish distribution at a habitat scale.

Spatial and temporal variation, and factors influencing the structure of intertidal rockpool fish assemblages were quantitatively investigated at three large rocky headlands in south-eastern New South Wales, Australia. A total of 5244 fish from 46 species, mainly permanent intertidal residents from the families Clinidae, Blenniidae, Tripterygiidae, Gobiidae, Gobiesocidae and Girellidae, was caught in the rockpools. Numbers of species and individuals and dominance patterns of species showed significant variability within locations, possibly in response to variations in rockpool tidal height and volume, or environmental variables, such as temperature and dissolved oxygen. Species composition also differed among locations, probably as a result of availability of different habitats at each location, which may be preferred by different species. Fish assemblage structure was stable and persistent through time, presumably because rockpools are colonized only by species suitably adapted to the dynamic intertidal environment. Temporal variability in the abundance of some common species occurred during summer and autumn, mainly owing to recruitment of resident fishes. Directions for future research are given, which may contribute to an understanding of the processes that underpin these patterns.

Beds of the seagrass Zostera capricorni are an integral part of the estuarine landscape along the east coast of Australia, forming an important habitat for juvenile fish. Seagrass beds can vary in their size, shape and patchiness of seagrass cover as well as their distance from the estuary mouth. We tested for a correlation between these features and small fish assemblages in seagrass. Fifteen beds were selected from three size-categories (small, 980 to 2300 m2; medium, 3375 to 4090 m2; and large, 5335 to 6630 m2). We found that the size of beds, the patchiness of seagrass cover and location within the estuary (distance from estuary mouth) were all related to differences in fish assemblages. There were greater densities of fish species in small (10.3 ±0.79 species .net-1) compared to medium (7.6 ±0.6) and large (8.2 ±0.5) beds. This occurred regardless of bed placement within the estuary, its patchiness or time of sampling (day and night). The fish assemblages within seagrass beds also changed as bed distance to estuary mouth increased. Six species had greater densities in beds closer to the estuary mouth, while only two species were in greater densities far from the mouth. Fish assemblages were different between beds with patchy and continuous cover, although total densities of all fish species combined were similar. There were greater densities of four species in continuous beds compared to two species that were greater in patchy beds. Overall, an important finding was that even small patchy seagrass beds contain greater densities of small fish species than larger beds with continuous seagrass cover.

Knowing where species are and understanding why is paramount for developing relevant and sustainable conservation and resource management strategies. The need for this information is becoming urgent as fishing activity, resource extraction and the impacts of coastal developments continue to put marine resources under increasing pressure. As logistical and financial constraints can restrict our ability to collect data in the marine environment, the ability to predict distributions based on known associations with different environmental variables would enhance our capacity to manage these resources. Before attempting to predict the distribution of species and groups of species, the underlying species-environment relationships must be examined to determine whether associations between species and the environment can: (i) be identified, (ii) be used to develop models that can accurately predict distributions, and (iii) are general enough to allow accurate predictions beyond the sampled area. Most studies to date have compared the composition of fish assemblages between sites to determine how different environmental variables influence distribution. While widely applied, these methods do not consider how individual species respond to multiple environmental gradients and they lack the ability to predict distributions across different combinations of variables along those gradients. This lack of prediction also limits our capacity to assess what marine biodiversity is presently threatened by global, regional, and local human pressures on marine ecosystems. '...' Thus, summarising and modelling species data at higher levels would result in models with poorer predictive accuracy and a loss of ecological information. The generality of the species-environment relationships defined by the models were assessed by evaluating the transferability of models between different areas. Models developed from data collected over a wider geographic extent could more accurately predict the distribution of species across a smaller spatial extent than vice versa. This indicated that while general theories of the ecology of temperate demersal fish can be defined, the actual patterns of distribution may vary from site to site, suggesting caution when using predictions beyond the sampled area for management purposes. Overall, species distribution modelling identified how different species and groups of species responded to the combined influence of multiple environmental gradients and was able to accurately predict distributions based on the defined associations. Their application has led to a greater understanding of the species environment relationships and will help to identify those areas that may be important for conservation. Their predictive ability will allow general predictions of distribution of fish species across unsurveyed areas and provides the ability to assess the potential impact from implementing different policy and management strategies.

The way in which "estuarine-dependent" fish use selected permanently open, seasonally open, and normally closed estuaries, and inshore marine waters is discussed. Attention is initially focused on the impact of reducing the connection between the sea in those estuaries in which bars tend to form at their mouths, and the effect of the resultant fluctuations in salinity on the composition and abundance of the estuarine fish community. Many of the commercially important and alleged "estuarine-dependent" marine species utilise nearshore marine habitats as an alternative to those provided by estuaries, even when a bar does not prevent access to the estuary. Many of these nearshore marine habitats, particularly the surf-zone, often harbour large accumulations of detached macrophyte detritus. Most of the fish caught in the surf-zone were represented by juveniles, and a number were important commercial species that were also abundant in estuaries. The total number of fish was strongly correlated with the amount of detached macrophytes present. The dominant species caught fell into two groups, i.e. those that were equally abundant in weeded and non-weeded surf-zones, and those that were almost exclusively found in weed. Dietary analyses of fish, allied with the large numbers of pisciverous cormorants present, show that the weed in the surf-zone provides a rich feeding site and suggests that it is a refuge from diurnal predation. The number of the commercially important Cnidoglanis macroceQhalus (mainly O+) was positively correlated with both the volume of fine red algae and dead seagrass. These respective two components of the drift have been shown to provide a habitat and food supply for the amphipod Allochestes comQressa, which is a major food item of the surf-zone populations of C.macrQQeQhalus. The contribution of the weight and value of "estuarine-dependent" finfish species to the total commercial fishery of temperate Western Australia was shown to be 20.3 and 2.4% respectively. Since many "alleged" "estuarine-dependent" species also use protected inshore marine waters as nursery areas in both south-western Australia and in other regions of temperate Western Australia where estuaries are absent, these species cannot be considered to be entirely dependent on estuaries. It is therefore preferable to regard these species as "estuarine-opportunists".

Anthropogenic climate change is one of the main challenges affecting the globe, with particular implications for the oceans. Marine climate change research has moved forward rapidly in recent years, and a range of physical model outputs are available that can be used by ecologists to help predict how species might be affected into the future. Policy makers require a level of understanding of how certain species and their ranges might change so that they can respond with sustainable management actions. This thesis aims to make use of a number of modelling techniques to explore implications of past and future conditions for marine species, and to appraise those tools that can be used under differing circumstances. Policy questions are answered relating to changes in the abundance and distribution of marine species. The links between historical climatic conditions and Barents Sea cod abundance are explored using Generalised Additive Models using data collected in the middle of the 20th century. This valuable historical data indicated that cod have temperature preferences and expand and shift their distributions based on environmental conditions. A simpler modelling technique is used to examine how oxygen conditions have changed in recent decades in the North Sea, how they might change in the future, and what implications this has for commercial fish species. The models show that oxygen conditions have improved recently and that they will not decrease to levels that result in large negative effects in the coming century. Species distribution modelling using a combination of global and downscaled model outputs shows that the UK will become more suitable for some non-native and harmful algal species in the 21st century, and less suitable for others. The model outputs contribute to the understanding of climate change effects and development of management tools to ensure the resilience of marine ecosystems into the future.

A total of 670 critical thermal maxima (CTMax) and minima (CTMin) were determined for three freshwater fishes acclimated to three constant temperatures and a diel regimen cycling between the lowest and highest acclimation temperatures. In all species temperature tolerance was directly related to acclimation temperature and slopes relating these variables indicate that acclimation temperature has a greater influence on tolerance of low rather than high temperatures. CTMax and CTMin values generated following exposure to 32 days of oscillating temperatures indicate that in general, fishes had temperature tolerance acclimation states consistent with the average temperature and not either the highest or lowest temperature of the diel cycle.

Rivulus marmoratus (Cyprinodont; Aplochelidae) is the only vertebrate known to reproduce by obligate internal self-fertilization. Selfing is the ultimate form of inbreeding and leads to virtual homozygosity in approximately ten generations, so that this mode of reproduction is effectively clonal. Populations of this species consist of arrays of homozygous clones, with high clonal diversity and low representation of each clone. Males occur at low frequency (<1%) in most populations, with a few notable exceptions. Females have never been recorded.High frequencies of males have been reported on two occasions; high numbers of males were reported on the island of Curacao in the 1970's, and males comprised up to 24% of the populations sampled on several Belize Cays during 1990-91. Hermaphrodites collected from one island, Twin Cays, proved to be heterozygous at mini-satellite loci when progeny tested and DNA fingerprinted. This was evidence that recent outcrossing had occurred.Earlier experiments with Floridian clonal lines had suggested that sex in this species was thermolabile; incubation of embryos at low temperatures (19° C)) produced up to 100% males. It was suggested that this might be part of an environmental sex determination (ESD) system in this species.If the induction of males is indeed part of and ESD in this species, then it may be that the temperature at which males are induced in a particular clone will be related to the temperature regime that clone encounters in nature. Therefore, it was hypothesized that the temperature at which males are induced would be related to the geographic origin of each clone, so that clones from the cooler extremes of the range would produce males at a lower threshold temperature than clones from the more equatorial center of the range. This study used laboratory reared descendants of clones from Vero Beach, Florida, Rio de Janiero, Brazil (the extreme north and south of the range), and from several Belize barrier islands and the Belize mainland (near the center of the range) in an effort to detect differences in the production of males between clonal lines based on their geographic origin. Eggs were collected from these hermaphrodites and incubated at 26° C)C, 22.5° C), or 19 ° C), representing normal, and below average temperatures for this species. These embryos were hatched and reared to sexual maturity at which time their sex was evaluated.Incubation at 26° C) resulted in 2-17% males, incubation at 22.5° C) resulted in 6-53% males, and incubation at 19° C) resulted in 47-74% males. However, the variation in male induction between clonal lines did not correspond to a geographic hypothesis.Also, significant numbers of deformed individuals were noted, particularly among individuals incubated at the lower two temperatures. Incubation at 26° C) resulted in 0-24% deformed, incubation at 22.5° C) resulted in 6-66% deformed, and incubation at 19° C) resulted in 36-87% deformed. It is clear that development at these lower temperatures is difficult for this species, and it may be that low temperature developmental stress is not a general challenge to this species.
Master of Science

Dans le contexte actuel de surpêche et de réchauffement climatique, il est nécessaire d’adopter une gestion écosystémique des ressources halieutiques. Ce travail de thèse apporte des éléments de réponse à cette problématique en se penchant sur le cas de la pêcherie crevettière guyanaise et de son impact sur les communautés de poissons associées. Comme dans la plupart des régions tropicales, les eaux côtières de Guyane se sont réchauffées d’environ 1°C entre 1990 et 2017. En revanche, comme dans peu d’endroits au monde, la pression de pêche s’est quasiment effondrée sur cette même période. Ce cas d’étude est donc une bonne opportunité pour comprendre la réaction des communautés de poissons de cette région tropicale après une diminution progressive et à grande échelle de la pression de pêche dans un contexte de réchauffement climatique. Les résultats de ce travail montrent que les facteurs environnementaux jouent un rôle dominant dans la structuration des communautés de poissons marins en Guyane. Les analyses montrent notamment des augmentations de certains indicateurs de diversité, une augmentation du spectre des tailles maximales théoriques des espèces et une augmentation de la redondance fonctionnelle qui est un facteur clé pour la stabilité des peuplements. Ces éléments témoignent d’une restructuration des communautés et mettent en avant leur capacité à retrouver un état riche et stable en une période relativement courte d’une douzaine d’années voire moins. On observe néanmoins une tropicalisation des communautés qui pose des questions sur l’évolution future de la diversité des écosystèmes tropicaux au regard des différents scénarios climatiques
In the actual context of overfishing and climate change we need to develop an ecosystem-based management of fisheries. This thesis work will try to bring answers to this issue by analyzing community assembly and the impact of French Guiana’s fishery on fish communities. As most of tropical regions, coastal waters in French Guiana have been subjected to an increase in temperature around 1°C between 1990 and 2017. However, as for only a few regions in the world, fishing pressure has collapsed in French Guiana during the same period. This case study is therefore a good opportunity to understand how tropical fish communities have responded to a progressive decreasing fishing pressure on a large scale and under climate change constraints. The aim of this work is to provide useful information for tropical fisheries with similar characteristics which tend to a more efficient ecosystem-based management with lower fishing pressure. The study showed that the environment plays a dominant role in community structure and that it has become more important over time. Results showed also significant increases in several diversity indices and an increase in theoretical maximum size spectra of surveyed fish which indicates a restructuring of communities. This recovery is associated with an increase of functional redundancy which is a key factor for the stability of ecosystems. Global results showed a great recovery capacity towards a richer and more stable state of communities in a relatively short period of time around 10 years

Tese de Doutoramento, Ciências do Mar, da Terra e do Ambiente, Ramo: Ciências do Mar, Especialização em Ecologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016
Recruitment of marine fish is composed of several steps, e.g. larval dispersal, metamorphosis to the juvenile stage, settlement and post-settlement. Each step is influenced by biotic and abiotic mechanisms, leading to a large variability of recruitment in space and time. Recruitment is a highly complex ecological process that has an essential impact on the demography, dynamics, persistence and overall genetic structure of a population and on the connectivity among populations. Regarding demersal and benthic fish species the dispersal of eggs and larvae describes the main form of gene flow among populations and facilitates connectivity among populations. Our level of knowledge on patterns of recruitment, dispersal and connectivity of fish differs between tropical and temperate marine systems, especially regarding the nearshore system. Most recruitment studies from temperate areas have analysed pelagic species and demersal species of sandy bottoms that are of commercial interest. While studies on recruitment patterns of fish inhabiting reef systems have been conducted mostly in tropical systems, in temperate areas such studies, in particular with a fine time scale are less common. One reason might be that traditional sampling methods (e.g. underwater visual census) are difficult to operate in the temperate nearshore due to harsher sea conditions (strong wind, waves, and currents and low visibility). Furthermore, several previous studies have highlighted the lack of knowledge on larval dispersal and population connectivity for temperate demersal fish. Therefore, the objectives of this thesis were i) to study temporal and spatial patterns of recruitment of rocky reef associated and coastal fish species at a nearshore rocky reef; ii) to analyse the influence of environmental processes on temperate fish recruitment at a small within season and a larger inter-annual scale; iii) to describe early life history traits that can be relevant to recruitment and iv) to estimate larval dispersal and population connectivity of an intertidal rocky reef fish species along the south west Iberian Peninsula. In this thesis, the main study area was the Arrábida Marina Park at the dynamic west coast of Portugal which is part of the Iberian Peninsula Upwelling System. Here, the recruitment of a temperate nearshore fish assemblage was studied at various spatial and temporal scales by sampling fish with standardized collectors filled with artificial substrate. This included the analysis of recruitment patterns in relation with oceanographic processes through generalized additive modelling and multivariate analysis and the study of early life history traits (ELHT). Moreover, population connectivity and larval dispersal of a common intertidal reef fish were investigated through an interdisciplinary approach combining indirect and direct genetic tools with bio-physical modelling. Standardized recruitment collectors filled with plastic substrate and installed in the water column (SMURFs), performed better than other types investigated, mainly due to easier handling and replicability. This collector type was then used throughout the thesis and for the first time this type of recruit collector, registered as well the recruitment of a pelagic fish species, Trachurus trachurus. This was the most abundant species, followed by the benthopelagic Serranus hepatus and various other cryptobenthic and benthopelagic species. At a temporal scale, recruitment varied highly between weeks within the summer recruitment season and between three consecutive years of monitoring. Temporal variation of recruitment was found at a species level, but also on the structure of the recruitment assemblage and on the composition of biogeographic species groups. More temperate fish were collected in 2012 than in 2011 and 2013. On the other hand more warm-temperate fish were found in 2013. Within the study area, the recruitment pattern was highly patchy at a fine spatial scale (~20 m) but less different at a larger scale (1-10 km). Recruitment patterns were related with environmental conditions. The inter-annual variation of the structure of the recruitment assemblage was related to the environmental variables up-welling, SST and surface current. But, the interaction between abiotic factors and recruitment differed among species. Highest abundance of T. trachurus recruits was registered in 2011 and in this year recruitment peaks of T. trachurus occurred around the new moon phase. Additionally, recruitment was negatively correlated with upwelling. Four hatching cohorts were estimated through backcalculation of the hatching date and individuals from these cohorts differed regarding ELHTS. For example, the first cohort had a faster early fish growth. The larval dispersal and population connectivity study of this thesis indicated highly connected populations and potentially long-distance larval dispersal of the common rocky intertidal fish, Lepadogaster lepadogaster, despite its short pelagic larval duration. Still, the dispersal model revealed higher probabilities for larval retention and exponentially declining probabilities of dispersal with distance and the parentage analysis resulted in self-recruitment and short larval dispersal. These results indicate that both local recruitment and long-distance dispersal can play an important role in the replenishment of a population. Moreover, the population differentiation and patterns of larval dispersal of L. lepadogaster were highly variable between years and this could be explained by inter-annual variation in current patterns. In summary, in this thesis settlement (reef fish), nearshore recruitment (T. trachurus) and larval dispersal (L. lepadogaster), which can contribute to the overall patterns of recruitment of fish populations, exhibited clear temporal patterns. Furthermore, various interactions of these processes with abiotic factors were found, which highlight the important role of oceanographic processes in mediating patterns of recruitment and larval dispersal. Results are discussed in relation to variation of the adult’s reef fish assemblage of the Arrábida Marine Park and why the gained understanding is important for fishery and conservation management. Since knowledge on coastal fish recruitment, population connectivity and larval dispersal is available mostly for tropical coral reef systems, findings of this thesis can help to broaden our understanding of patterns and processes in temperate reef systems. Overall, this thesis demonstrates that a multidisciplinary study approach, combining ecology, oceanography and genetics, is necessary to improve our understanding of the highly complex, interactive process of recruitment.
O recrutamento dos peixes marinhos depende de várias fases e processos como a dispersão larvar, a metamorfose do estado larvar para juvenil, o assentamento para o habitat bentónico ou processos pós-assentamento. Cada uma destas etapas é influenciada por mecanismos bióticos e abióticos, podendo o recrutamento apresentar uma elevada variação espáciotemporal. É um processo ecologicamente complexo, com um impacto fundamental na demografia, dinâmica, persistência, conectividade e estrutura genética das populações. Em espécies de peixes bentónicos, a dispersão de ovos e larvas é o principal processo que potencialmente permite o fluxo genético e a conectividade entre populações. O conhecimento geral acerca dos padrões de recrutamento, dispersão e conectividade de espécies de peixes que vivem associadas a recifes costeiros difere entre sistemas tropicais e temperados; nestes últimos, a maioria dos estudos sobre recrutamento centra-se em espécies pelágicas e demersais de substratos arenosos com valor comercial, enquanto que nas regiões tropicais a maioria dos estudos centra-se em sistemas de recife e geralmente numa escala temporal mais fina. Os métodos de amostragem tradicionais (censos visuais), são difíceis de replicar em regiões temperadas devido às condições mais adversas destes sistemas junto à costa (vento, correntes e ondulação fortes e baixa visibilidade). Adicionalmente, há poucos trabalhos sobre processos de dispersão larvar e conectividade entre populações de peixe demersais nestes sistemas. Esta tese tem como objetivos: i) o estudo de padrões espáciotemporais de recrutamento de espécies de peixe costeiras e associadas a recifes rochosos; ii) a análise da possível influência de processos ambientais na variação temporal do recrutamento intrasazonal e interanual; iii) descrever características dos estados iniciais de desenvolvimento relevantes para o recrutamento; iv) estimar a dispersão larvar e conectividade entre populações de espécies de peixe dos recifes rochosos do intertidal, ao longo do sudoeste da Península Ibérica. A principal área de estudo foi o Parque Marinho Professor Luiz Saldanha (costa oeste de Portugal), que pertence ao sistema de “Upwelling” da Península Ibérica. Estudou-se o recrutamento de peixes costeiros junto à costa, a várias escalas espácio-temporais, através de amostragem com coletores estandardizados com substratos artificiais (SMURFS). Analisou-se a relação entre os padrões de recrutamento e os processos oceanográficos através de modelos aditivos generalizados, análise multivariada e estudo das características dos estados iniciais (ELHT). Para além disto, investigaram-se os padrões de conectividade entre populações e de dispersão larvar de uma espécie comum no intertidal rochoso, através de uma abordagem interdisciplinar combinando ferramentas genéticas diretas e indiretas com modelação biofísica. Os SMURFS testados com substrato plástico no seu interior, apresentaram maior facilidade de manuseamento e replicabilidade do que os SMURFS com outros materiais testados, pelo que foram utilizados como método principal. Este trabalho permitiu, pela primeira vez a monitorização do recrutamento de uma espécie de peixe pelágica com SMURFS, Trachurus trachurus (carapau); foi a espécie mais abundante ao longo de todo o estudo seguida da espécie bentopelágica Serranus hepatus e de outras espécies criptobênticas e bentopelágicas. O recrutamento apresentou uma variação elevada entre semanas e entre os três anos consecutivos de monitorização. Verificou-se igualmente uma variação temporal no recrutamento ao nível da espécie, da estrutura da assembleia de recrutas e nos grupos de espécies de acordo com a composição biogeográfica. Em 2012, registaram-se mais espécies de climas temperados do que em 2011 e 2013, sendo que em 2013 registaram-se mais espécies de climas temperados quentes. Quanto à variação espacial, o padrão de recrutamento foi altamente irregular a uma pequena escala mas pouco variável quando analisado a uma escala mais alargada. A variação interanual da estrutura da assembleia de recrutamento coincidiu com a variação dos padrões de “upwelling”, temperatura e correntes superficiais. A interação entre fatores abióticos e recrutamento foi também distinta entre diferentes espécies. Em 2011, registou-se a maior abundância de recrutas de carapau, durante as fases de lua nova; o recrutamento desta espécie apresentou uma correlação negativa com o “upwelling”. Foram estimadas quatro coortes à eclosão através de retrocálculo da data de eclosão, sendo que os indivíduos da primeira coorte apresentavam características (ELHT) distintas, como por exemplo um crescimento larvar mais rápido, do que os indivíduos das restantes coortes. O estudo da dispersão larvar e conectividade entre populações da espécie Lepadogaster lepadogaster revelou a existência de populações com elevado nível de conectividade e um potencial de dispersão larvar de longa distância, apesar da sua curta duração larvar pelágica. Apesar disto, o modelo de dispersão revelou uma probabilidade alta de ocorrência de retenção larvar e probabilidade exponencialmente decrescente de dispersão com o aumento da distância; do mesmo modo, os resultados da análise parental indicaram a existência de retenção larvar, com baixa dispersão. Assim sendo, tanto o recrutamento local como a dispersão de longa distância podem ter um papel importante na sustentabilidade destas populações. Contudo, a diferenciação de populações e padrões de dispersão larvar de L. lepadogaster apresentaram uma variação elevada entre anos, o que pode ser explicado pela variação interanual dos padrões das correntes. Em resumo, foram encontrados padrões temporais evidentes nos processos de assentamento (nos peixes de recife), recrutamento (carapau) e dispersão larvar (L.lepadogaster), que podem contribuir para os padrões gerais de recrutamento das populações de peixe. Adicionalmente, as diferentes interações destes processos com os fatores abióticos encontradas, indicam uma importante influência das condições oceanográficas nos padrões de recrutamento e dispersão larvar. Os resultados são discutidos em relação à informação disponível sobre as assembleias de espécies que vivem associadas aos recifes na área de estudo e em relação à sua importância para o delineamento de estratégias de gestão de pesca e de conservação. Os resultados desta tese contribuem para aumentar o conhecimento e compreensão de padrões e processos que influenciam o recrutamento de peixes associados a recifes em regiões temperadas, uma vez que a informação disponível sobre os padrões de recrutamento costeiro, conectividade entre populações e dispersão larvar de espécies neste tipo de ambientes é menor do que a exsitente para recifes tropicais. Esta tese demostra a importância de uma abordagem interdisciplinar que combine aspectos da ecologia, oceanografia e genética, para aumentar a compreensão da complexidade e interacções ubjacentes aos processos de recrutameto dos peixes costeiros.

Species invasions have historically driven many natural communities around the world into collapse. As climate changes, species are shifting their distribution to regions with more tolerable conditions, intensifying species invasion rates. By feeling the heat, many marine tropical species are moving towards cooler environments. When extending their ranges they are forced to interact and share habitats and resources with native species, potentially triggering modifications in the structure and functionality of temperate communities. For at least two decades, hundreds of tropical fish species have been recruiting to Australian temperate reefs, but successful colonisation depends on how they respond to and cope with unfamiliar environmental conditions. Temperate ecosystems represent a potential hostile environment for tropical species, due to novel prey, predators, competitors, habitats, and suboptimal temperatures. This thesis provides empirical evidence that behavioural traits and biological interactions are underpinning mechanisms controlling the success of tropical fish establishment in temperate waters, and demonstrates some degree of resistance by temperate fish communities to tropical invasions. By assessing a wide range of behavioural responses of temperate and tropical fishes across a temperature gradient from low to high latitudes along the eastern Australian coast, I reveal that behavioural plasticity, generalism and segregation of tropical and temperate species at their leading and trailing edges, respectively, might facilitate coexistence in temperature mixing zones (Chapter 2). In contrast, tropical fish are more riskaverse at leading edges and such behaviour was associated with reduced foraging, possibly compromising their permanent establishment on temperate reefs under current warming (Chapter 3). I further reveal that physical (low temperature and/or unfamiliarity with temperate environmental conditions) and biological (behaviour and abundance of temperate competitors) effects reduce the efficiency of tropical fishes in their food acquisition, which may compromise their fitness delaying their establishment in temperate environments nowadays (Chapter 4). Whilst warming has led to the expansion of sea-urchin barrens in temperate regions, which creates suitable habitats for tropical fish colonisation, future ocean acidification may inhibit the formation of such habitats, reducing the probability of successful recruitment of tropical fishes and the emergence of novel fish community structures (Chapter 5). Although some biological and physical processes may slow the pace of tropicalisation, under future ocean warming tropical fishes may no longer struggle for survival in coolertemperate water, which has historically been acting as the main barrier against the tropicalisation of temperate ecosystems. Yet, ocean acidification can slow down the process of tropicalisation at the leading edges of species ranges.
Thesis (Ph.D.) -- University of Adelaide, School of Biological Science, 2020

The accurate identification of fish ‘ear-bones’, known as otoliths, is essential to determine the fish prey of marine and terrestrial predators. Fish otoliths are species-specific when combining size, shape and surface features, and can remain undigested for long periods. As a result, they can indicate which fish make up the diet of various predators, including cephalopod, seabird, marine mammal and fish species. Such studies are crucial for understanding marine ecosystems, and trophodynamics in particular. Increasingly, these methods are being used to understand the diet of some terrestrial predators, also extending to that of humans in archaelogical studies. Otoliths of Common Australian Temperate Fish offers users a verified reference collection to assist in the accurate identification of species and size of fish using otoliths. It covers 141 fish species from a broad geographic range of the Australian temperate region and includes commercial and non-commercial fish species. A standardised written description of the otolith structure, size and surface features is provided for each species. Included are brief distribution and ecology notes, and regression for both otolith and fish lengths, together with high-quality SEM photographs of the otolith described. This guide will be an essential reference for marine scientists and marine mammal researchers; ornithologists, fisheries researchers and fish biologists studying age and growth or comparative anatomy; and archaeologists. Winner of the 2008 Whitley Award for Zoological Manual.

Estuarine and coastal waters are acknowledged centres for anthropogenic impacts. Superimposed on the complex natural interactions between land, rivers and sea are the myriad consequences of human activity – a spectrum ranging from locally polluting effluents to some of the severest consequences of global climate change. For practitioners, academics and students in the field of coastal science and policy, this book examines and exemplifies current and future challenges: from upper estuaries to open coasts and adjacent seas; from tropical to temperate latitudes; from Europe to Australia. This authoritative volume marks the 50th anniversary of the Estuarine and Coastal Sciences Association, and contains a prologue by founding member Professor Richard Barnes and a short history of the Association. Individual chapters then address coastal erosion and deposition; open shores to estuaries and deltas; marine plastics; coastal squeeze and habitat loss; tidal freshwaters – saline incursion and estuarine squeeze; restoration management using remote data collection; carbon storage; species distribution and non-natives; shorebirds; Modelling environmental change; physical processes such as sediments and modelling; sea level rise and estuarine tidal dynamics; estuaries as fish nurseries; policy versus reality in coastal conservation; developments in Estuarine, coastal and marine management.

In 2001, taxonomic reorganization of the bacterial genera Anaplasma, Ehrlichia, Cowdria and Neorickettsia resulted in the transfer of numerous species between these taxa, and the renaming of the transferred species to reflect their new taxonomic position (Dumler et al. 2001). Among the members of these genera, there are four species of established zoonotic importance, which are therefore the subject of this chapter. Two of these species were affected by the changes outlined above.Although these four species possess markedly different ecologies, they share the fundamental biological character of being obligate intracellular bacteria that reside within vacuoles of eukaryotic cells. This lifestyle underlies their fastidious nature in the laboratory and hence our limited knowledge of their biology and pathogenicity. Nonetheless, despite this shortfall, all four are associated with diseases of established or emerging importance: E. chaffeensis provokes human monocytic ehrlichiosis (HME), E. ewingii causes human ewingii ehrlichiosis (HEE), A. phagocytophilum causes human granulocytic anaplasmosis (HGA), N. sennetsu is the agent of sennetsu neorickettsiosis.The first three pathogens are transmitted by hard (ixodid) ticks and are encountered across the temperate zones of the northern hemisphere (and maybe beyond), although the vast majority of human infections caused by them are currently reported in the USA. There, HME and HGA are second only to Lyme disease (caused by Borrelia burgdorferi) in terms of public health significance. Furthermore, given that there is evidence of increasing population sizes and changing distributions for ixodid species (Scharlemann et al. 2008), it is not unreasonable to predict that the infections they transmit will present an increased medical burden in the future. N. sennetsu remains an enigmatic pathogen; case reports remain scarce, but serological surveys suggest high levels of exposure. The widespread consumption of raw fish across east Asia presents specific infection risks to this region, and an increased awareness that sennetsu neorickettsiosis is among the infections that can be acquired from this source is required before its public health importance can be accurately assessed.

Post-glacial aquatic ecosystems in Eurasia and North America, such as the Baltic Sea, evolved in the freshwater, brackish, and marine environments that fringed the melting glaciers. Warming of the climate initiated sea level and land rise and subsequent changes in aquatic ecosystems. Seminal ideas on ancient developing ecosystems were based on findings in Swedish large lakes of species that had arrived there from adjacent glacial freshwater or marine environments and established populations which have survived up to the present day. An ecosystem of the first freshwater stage, the Baltic Ice Lake initially consisted of ice-associated biota. Subsequent aquatic environments, the Yoldia Sea, the Ancylus Lake, the Litorina Sea, and the Mya Sea, are all named after mollusc trace fossils. These often convey information on the geologic period in question and indicate some physical and chemical characteristics of their environment. The ecosystems of various Baltic Sea stages are regulated primarily by temperature and freshwater runoff (which affects directly and indirectly both salinity and nutrient concentrations). Key ecological environmental factors, such as temperature, salinity, and nutrient levels, not only change seasonally but are also subject to long-term changes (due to astronomical factors) and shorter disturbances, for example, a warm period that essentially formed the Yoldia Sea, and more recently the “Little Ice Age” (which terminated the Viking settlement in Iceland).There is no direct way to study the post-Holocene Baltic Sea stages, but findings in geological samples of ecological keystone species (which may form a physical environment for other species to dwell in and/or largely determine the function of an ecosystem) can indicate ancient large-scale ecosystem features and changes. Such changes have included, for example, development of an initially turbid glacial meltwater to clearer water with increasing primary production (enhanced also by warmer temperatures), eventually leading to self-shading and other consequences of anthropogenic eutrophication (nutrient-rich conditions). Furthermore, the development in the last century from oligotrophic (nutrient-poor) to eutrophic conditions also included shifts between the grazing chain (which include large predators, e.g., piscivorous fish, mammals, and birds at the top of the food chain) and the microbial loop (filtering top predators such as jellyfish). Another large-scale change has been a succession from low (freshwater glacier lake) biodiversity to increased (brackish and marine) biodiversity. The present-day Baltic Sea ecosystem is a direct descendant of the more marine Litorina Sea, which marks the beginning of the transition from a primeval ecosystem to one regulated by humans. The recent Baltic Sea is characterized by high concentrations of pollutants and nutrients, a shift from perennial to annual macrophytes (and more rapid nutrient cycling), and an increasing rate of invasion by non-native species. Thus, an increasing pace of anthropogenic ecological change has been a prominent trend in the Baltic Sea ecosystem since the Ancylus Lake.Future development is in the first place dependent on regional factors, such as salinity, which is regulated by sea and land level changes and the climate, and runoff, which controls both salinity and the leaching of nutrients to the sea. However, uncertainties abound, for example the future development of the Gulf Stream and its associated westerly winds, which support the sub-boreal ecosystems, both terrestrial and aquatic, in the Baltic Sea area. Thus, extensive sophisticated, cross-disciplinary modeling is needed to foresee whether the Baltic Sea will develop toward a freshwater or marine ecosystem, set in a sub-boreal, boreal, or arctic climate.

Freshwater ecosystems are particularly susceptible to invasions by invasive non-native species (INNS) across a range of taxa, largely as a consequence of anthropogenic influences on these systems, with a number of ecological and socio-economic impacts. This chapter reviews freshwater invasive non-native species across the globe, focusing on fishes, invertebrates, floating macrophytes, and submerged macrophytes emphasising the knowledge gaps in particular that have resulted in biases inherent in assessments of freshwater invasions. These include an ecological bias because the majority of studies focus on terrestrial invasions; a geographical bias as most studies are focused on temperate northern hemisphere systems; and a taxon bias where fish invasions, populate the literature. This chapter highlights some of the approaches needed to survey, monitor, and manage INNS.

<em>Abstract</em>.—Five conceptual models of longitudinal fish community organization in streams were examined: (1) niche diversity model (NDM), (2) stream continuum model (SCM), (3) immigrant accessibility model (IAM), (4) environmental stability model (ESM), and (5) adventitious stream model (ASM). We used differences among models in their predictions about temporal species turnover, along with five spatiotemporal fish community data sets, to evaluate model applicability. Models were similar in predicting a positive species richness–stream size relationship and longitudinal species nestedness, but differed in predicting either similar temporal species turnover throughout the stream continuum (NDM, SCM), higher turnover upstream (IAM, ESM), or higher turnover downstream (ASM). We calculated measures of spatial and temporal variation from spatiotemporal fish data in five wadeable streams in central and eastern North America spanning 34–68 years (French Creek [New York], Piasa Creek [Illinois], Spruce Run [Virginia], Little Stony Creek [Virginia], and Sinking Creek [Virginia]). All streams exhibited substantial species turnover (i.e., at least 27% turnover in stream-scale species pools), in contrast to the predictions of the SCM. Furthermore, community change was greater in downstream than upstream reaches in four of five streams. This result is most consistent with the ASM and suggests that downstream communities are strongly influenced by migrants to and from species pools outside the focal stream. In Sinking Creek, which is isolated from external species pools, temporal species turnover (via increased richness) was higher upstream than downstream, which is a pattern most consistent with the IAM or ESM. These results corroborate the hypothesis that temperate stream habitats and fish communities are temporally dynamic and that fish migration and environmental disturbances play fundamental roles in stream fish community organization.

<em>Abstract</em>.—Mangrove ecosystems are being lost globally at an alarming rate due to deforestation, reclamation, and urbanization. Not only is the loss of these ecosystems detrimental to the commercially and ecologically important marine species they support, there is also a reduction in the ecosystem services they provide, namely mitigating rising carbon dioxide levels by serving as carbon sinks. These ecosystems, labeled as “blue carbon” sinks, potentially sequester more than 10 times the carbon that tropical and temperate ecosystems do. Thus, conservation and restoration of these blue carbon sinks is imperative. We explored how much carbon is currently stored in dwarf red mangrove <em>Rhizophora </em>mangle biomass in tidal creeks of Eleuthera, Bahamas. In October of 2012, four sites were selected near Cape Eleuthera, maximizing site variability. All sampling was done from six plots established at each site. The quantity of carbon stored in mangroves was determined from plant biomass, which was extrapolated from plant volumes. Mangrove volumes were determined from growth parameters of individuals. It was observed that there were large differences from site to site in number of individuals, sediment depth, biomass accumulation, and carbon allocation of mangroves, but the total amount of carbon stored from site to site in mangroves did not differ. The site with the greatest biomass and carbon storage also had the greatest sediment depth, suggesting a correlation between the two. Regardless of the site to site variability, mangroves proved to be good stores for carbon. Future work should search for the factors that explain site to site variability.

<em>Abstract</em>.—Mangrove ecosystems are being lost globally at an alarming rate due to deforestation, reclamation, and urbanization. Not only is the loss of these ecosystems detrimental to the commercially and ecologically important marine species they support, there is also a reduction in the ecosystem services they provide, namely mitigating rising carbon dioxide levels by serving as carbon sinks. These ecosystems, labeled as “blue carbon” sinks, potentially sequester more than 10 times the carbon that tropical and temperate ecosystems do. Thus, conservation and restoration of these blue carbon sinks is imperative. We explored how much carbon is currently stored in dwarf red mangrove <em>Rhizophora </em>mangle biomass in tidal creeks of Eleuthera, Bahamas. In October of 2012, four sites were selected near Cape Eleuthera, maximizing site variability. All sampling was done from six plots established at each site. The quantity of carbon stored in mangroves was determined from plant biomass, which was extrapolated from plant volumes. Mangrove volumes were determined from growth parameters of individuals. It was observed that there were large differences from site to site in number of individuals, sediment depth, biomass accumulation, and carbon allocation of mangroves, but the total amount of carbon stored from site to site in mangroves did not differ. The site with the greatest biomass and carbon storage also had the greatest sediment depth, suggesting a correlation between the two. Regardless of the site to site variability, mangroves proved to be good stores for carbon. Future work should search for the factors that explain site to site variability.

<em>Abstract</em>.-The remarkable migrations of some fishes are still the subject of active research, but there has been much less attention on the evolutionary or behavioral origins of diadromous migrations. Diadromy likely evolved as a result of the adaptive advantage of using higher productivity habitats for growth, but the reason why the first individuals left their habitat to enter a new one is unknown. The objective of this paper is to examine the possible evolutionary and behavioral origin of diadromous fish migration and to explore the possible factors that could have led to the development of migratory behavior, using a behavioral model for a triggering mechanism of fish migration. Eels likely evolved in the tropics from a marine ancestor, and salmon evolved in temperate regions from a freshwater ancestor. Evidence of the ancestral life history states of these fishes can be seen in geographic clines of occurrence of nonmigratory residents of the sympatric Japanese eel <em>Anguilla japonica</em>, a catadromous species, and masu salmon <em>Oncorhynchus masou</em>, an anadromous species, with a higher proportion of resident type "sea eels" at higher latitudes, whereas masu salmon have more river residents at lower latitudes. The amphidromous ayu <em>Plecoglossus altivelis </em>was used as a model species for exploring the behavioral origins of migration. The triggering mechanism of upstream migration of ayu could be explained by a three-step model of necessary conditions for starting migration that include age and body size, endocrinological condition, and psychological processes. A behavioral model of drive was proposed to explain the last step that is influenced by exogenous/endogenous factors such as water temperature, fish density, and hunger level. The drive of upstream migration behavior appears to be a psychological repulsion that occurs in stressed fish when the behavioral rule of optimum interindividual distance is broken, since fish with stronger repulsion and a larger interindividual distance showed more active jumping behavior and stronger upstream migration. A vacuum activity of jumping behavior of ayu contained in a limited space occurred in random directions without any behavioral stimuli when water temperature increased. This vacuum activity can be interpreted as an escapement behavior of fish that bolt out of unfavorable environments, and this escapement might be a behavioral origin of fish migration that may also help to understand the evolutionary origin of migration (random escapement hypothesis).

<em>Abstract.</em>—Low water temperatures experienced by temperate fish during winter reduce muscle power, resulting in an important limitation to overwintering fishes that may explain why they often seek areas of reduced flow as winter refugia. The Hudson River is a heavily urbanized estuary, and as such, navigation and industrial influences may have particular importance to species seeking to overwinter there. In December 1995 and 1997, we used a mobile hydroacoustic survey, coupled with gill netting and midwater trawling for species identification, to identify the distribution and abundance of key species in the Hudson River. Striped bass <em>Morone saxatilis</em>, white perch <em>M. americana</em>, and bay anchovy <em>Anchoa mitchilli, </em>co-occurred in the lower 25 km of the river. Fish distributions were related to salinity. Striped bass and bay anchovy were found in highest densities in the lower river (Yonkers and Battery regions) and higher salinities. White perch dominated from Yonkers upriver. Acoustic population estimates of striped bass abundance from 1995 (576,110) compared favorably with a wintertime tagging study (949,000), but were grossly underestimated in 1997. Higher salinity in the Battery and Yonkers regions in 1997 may have pushed distributions of striped bass and white perch upriver compared to 1995 sampling and may have led to decreased precision in estimates. This study suggests that key Hudson River fish use much of the lower 61 km of the Hudson River as overwintering habitat.

The introduction of fish into the aquaculture of southern Russia is very important, given the fact that in recent years, in the period before the regulation of the Don runoff (1927-1952), fish catches were in the range from 110 tons to 590 tons, and the average long-term production in the Azov-Don region reached 270 tons. Don had a negative impact on the reproduction of fish. Dams prevent fish from accessing natural spawning grounds. The main goal of the study is experiments on growing young fish (Vimba vimba) on granular feed in a modernized facility to grow this valuable species. As a result of the experiment, we found that with the maintenance of fish spawners in RAS, better body weight gains were obtained than in running water. The delay in growth in the first case was associated with a decrease in the consumption and digestibility of the food eaten, as a result of a deterioration in water parameters associated with an increase in temperature and a deterioration in the gas regime.

The evaluation of the behaviours of fish which stand on higher levels of food-web is important from the viewpoint of the resource management or other environmental impacts. Especially for the adult fish which can swim against the currents of circumference, considering the migration effects in the model is quite significant. In the present study, a fish model is developed which considers the migration effect by modeling the preference for the environmental factors. As the target fish of modeling, Pagrus major is chosen because it is one of the representative species due to its high resource value. In the model, the direction of the fish movement is determined by the preference strength for the environmental factors such as water temperature, dissolved oxygen, prey density, and so on. The model is coupled with a hydrodynamic model and a lower-trophic ecosystem model which predict physical environment and water quality of the target area. Numerical simulations are carried out to reproduce the spatial distribution and seasonal variations of ecosystem in east Seto Inland Sea. As a result of the simulations, it is clarified that the both water temperature and prey density have large influence on migration and distribution of Pagrus major.

In order to develop a new technology for low-temperature preservation of fish reproductive cells, and sturgeon fish in particular, mathematical modeling of acoustic impact on biological objects has been performed. A mathematical model of cryoprotectant diffusion through the reproductive cell membrane is constructed. It is assumed that a special piezoactuator creates an acoustic field in the cryoprotectant. By virtue of this, the corresponding velocity field of the environment is assumed to be set. The resulting boundary value problem is solved numerically using the finite element method.

The effects of hydrogen charging as well as natural hydrogen escaping on fracture behavior of A508III steel at room temperature were investigated. The presence of hydrogen caused a slightly increase in yield strength and a distinct decrease in the elongation and reduction in area, but no or hardly any influence on the ultimate tensile strength (UTS). Non-charged specimen exhibited a ductile mode of failure with micro-void coalescence, while the H-charged specimens showed typical brittle fracture with “fish eye” appearance. The presence of hydrogen gave an increase in the dislocation density after tensile deformation. Nucleation of defects occurred primarily from the inclusions which contain complex oxides of Al, Mg and Ca, and (Ca, Mn)S, as well as MnS only to a small extent. The parameters of non-metallic inclusions, such as type, shape, size and content play the decisive role at the defect formation. In the process of natural H-escaping, the fracture surface characteristics of H-charged steels gradually transferred from brittle fracture mode to ductile fracture mode. At the same H-charged time, the H-escaping time required for the brittle-ductile transition was related to the H-charged current density.

In this article we analyse catfish rearing conditions in recirculating aquaculture systems (RAS). Based on research, performed by scientists from different countries, we evaluated optimal water parameter values for catfish rearing. African catfish growing process and with it associated factors were researched in JC ,,Šamas“. The amount of dissolved oxygen (on average 4,53 mg/l) in the rearing basin is adequate for the catfish to feel comfortable and for biomass growth. Water temperature only varies slightly – the average water temperature is 23,30C. The ideal pH for rearing fish in RAS is 7.0. Many aquaculture species continue to feel comfortable in pH boundaries of 6.5-8.5. In the samples, taken from catfish rearing system, the pH varied from 5.58 to 6.63. Such acidic water decreases the effectiveness of biological filter, but also decreases the toxic effect of excreted ammonia on the fish. Only a small amount of suspended solid is present in the samples, which means that they are being removed properly. The average amount of ammonia nitrogen in the water basins in analysed catfish rearing systems is 1,171 mg/l. The analysed water samples presented an average nitrite amount of 0,974 mg/l. The recommended amount of nitrites for catfish is less than 0.5 mg/l. The analysed samples presented relatively high nitrate values – from 412 to 495 mg/l. In order to decrease the concentration of accumulated nitrates it is required to change no less than 10% of total system water volume every day. The index of consumed biochemical oxygen corresponds to the requirements for water quality in RAS

The austenitic stainless steels have excellent mechanical and chemical characteristics and these materials are widely used for the main structural components in the nuclear power plants. A part of structural components using these materials is considered to have strain-history by machining, welding and etc in the process of manufacturing and these parts would be hardened because these materials have a remarkable work-hardening property. On the other hand, conventional studies for the fatigue strength used to be investigated by the results of fatigue tests applying normal specimens without the effect of hardening by pre-strain. This paper describes the effect of large pre-strain on very high cycle fatigue strength of the materials in consideration for the evaluation of strength of actual structures in the nuclear power plants. In order to achieve this purpose, the fatigue tests were carried out with strain hardened specimens. The material served in this study was type SUS316NG. Up to ±20% pre-strain was introduced to the round bar shaped materials by tension and compression load test, and the materials were mechanically machined to the hourglass shaped smooth specimens. On the other hand, the pre-strain of some specimens were introduced after machining so as to study the influence of roughness of the surface of the specimens for the fatigue property. Fatigue tests were conducted by ultrasonic and rotating-bending fatigue test machines and conditions were decided by preliminary examinations to control temperature elevation of the specimen during the fatigue test. The S-N curves obtained from fatigue tests show that increase in magnitude of the pre-strain cause increase in the fatigue strength of the material and this relationship is independent of type of the pre-strains of tension and compression. Though all specimens were fractured by the surface initiated fatigue crack, only one specimen was fractured by the internal crack and so-called “fish-eye” was observed on the fracture surface. However, the internal fracture of the SUS316NG does not cause sudden drop of the fatigue strength. Also, the Vickers hardness tests were carried out to discuss the relationship between fatigue strength and hardness of the pre-strained materials. It is found that the increase in fatigue limit of the pre-strained materials strongly depend on the hardness derived from the indentation size equals to the scale of stage I fatigue crack.

Silver salmon is usually cultured around the eastern coast of Tohoku Region in Japan. The smolt of silver salmon begins to be cultured in a cage from November. Currently, the aquaculture of silver salmon is terminated until the end of July due to high water temperature since silver salmon will die in a few days if the diurnal minimum water temperature becomes 21 or 22°C. Live salmon cannot be obtained around August because wild salmon is captured from September or October. In the present study, a submergible cage using flexible tubes is proposed to farm silver salmon in deeper and cooler waters in August. The cage was submerged and floated up by ejecting air from and injecting air into the flexible tubes, respectively. The flexible tubes were inserted into the polyethylene pipes. First, water tank test using the 1/3.64 scaled model was carried out in the Ocean Engineering Basin, Institute of Industrial Science, The University of Tokyo. The cage was submerged or floated up, changing the methods of air ejection or injection. The cage was submerged and floated up faster in case of two vents to increase the rate of air flow than in case of only one vent on flexible tubes. The submersion was also faster if the length of an injection tube between the vents and air compressor was shortened to reduce the pressure loss. However, the maximum inclination angle of the cage was determined by the diameter of the cage and the submerged depth, not depending on the methods of air injection or ejection. Similar results were observed in the field test. Consequently, silver salmon could be farmed in deeper and cooler waters until the middle of August. The inclination of the cage was not the problem for silver salmon, while it may have unfavorable effects on the other species through the deformation of netting. Hence, the methods to reduce the inclination of the cage in submerging or floating up operation should be considered and validated in field test in the future.

A fretting/wear degradation at the tube support in the U-bend region of a steam generator (SG) of a pressurized water reactor (PWR) has been reported. Simulated fretted flaws were machined on SG tubes of 195 mm in length. A pressure test was carried out with the tubes at room temperature by using a high pressure test facility which consisted of a water pressurizing pump, a test specimen section and a control unit. Water leak rates just after a ligament rupture or a burst were measured. Tubes degraded by up to 70% of the tube wall (TW) showed a high safety margin in terms of the burst pressure during normal operating conditions. Tubes degraded by up to 50% of the TW did not show a burst. Burst pressure depended on the defect depths rather than on the wrap angles. The tube with a wrap angle of 0° showed a fish mouth fracture, whereas the tube with a 45° wrap angle showed a three way fracture.

Channel Islands National Park (CHIS) has conducted long-term ecological monitoring of the kelp forests around San Miguel, Santa Rosa, Santa Cruz, Anacapa and Santa Barbara Islands since 1982. The original permanent transects were established at 16 sites between 1981 and 1986 with the first sampling beginning in 1982, this being the 33rd year of monitoring. An additional site, Miracle Mile, was established at San Miguel Island in 2001 by a commercial fisherman with assistance from the park. Miracle Mile was partially monitored from 2002 to 2004, and then fully monitored (using all KFM protocols) since 2005. In 2005, 16 additional permanent sites were established to collect baseline data from inside and adjacent to four marine reserves that were established in 2003. Sampling results from all 33 sites mentioned above are included in this report. Funding for the Kelp Forest Monitoring Program (KFM) in 2014 was provided by the National Park Service (NPS). The 2014 monitoring efforts utilized 49 days of vessel time to conduct 1,040 dives for a total of 1,059 hours of bottom time. Population dynamics of a select list of 71 “indicator species” (consisting of taxa or categories of algae, fish, and invertebrates) were measured at the 33 permanent sites. In addition, population dynamics were measured for all additional species of fish observed at the sites during the roving diver fish count. Survey techniques follow the CHIS Kelp Forest Monitoring Protocol Handbook (Davis et al. 1997) and an update to the sampling protocol handbook currently being developed (Kushner and Sprague, in progress). The techniques utilize SCUBA and surface-supplied-air to conduct the following monitoring protocols: 1 m2 quadrats, 5 m2 quadrats, band transects, random point contacts, fish transects, roving diver fish counts, video transects, size frequency measurements, and artificial recruitment modules. Hourly temperature data were collected using remote temperature loggers at 32 sites, the exception being Miracle Mile where there is no temperature logger installed. This annual report contains a brief description of each site including any notable observations or anomalies, a summary of methods used, and monitoring results for 2014. All the data collected during 2014 can be found in the appendices and in an Excel workbook on the NPS Integrated Resource Management Applications (IRMA) portal. In the 2013 annual report (Sprague et al. 2020) several changes were made to the appendices. Previously, annual report density and percent cover data tables only included the current year’s data. Now, density and percent cover data are presented in graphical format and include all years of available monitoring data. Roving diver fish count (RDFC), fish size frequency, natural habitat size frequency, and Artificial Recruitment Module (ARM) size frequency data are now stored on IRMA at https://irma.nps.gov/DataStore/Reference/Profile/2259651. The temperature data graphs in Appendix L include the same graphs that were used in past reports, but include additional violin plot sections that compare monthly means from the current year to past years. In addition to the changes listed above, the layout of the discussion section was reordered by species instead of by site. The status of kelp forests differed among the five park islands. This is a result of a combination of factors including but not limited to, oceanography, biogeography and associated differences in species abundance and composition, as well as sport and commercial fishing pressure. All 33 permanent sites were established in areas that had or were historically known to have had kelp forests in the past. In 2014, 15 of the 33 sites monitored were characterized as developing kelp forest, kelp forest or mature kelp forest. In addition, three sites were in a state of transition. Two sites were part kelp forest and part dominated by Strongylocentrotus purpuratus...

Theodore Roosevelt National Park (THRO) in western North Dakota was established for its historical connections with President Theodore Roosevelt. It contains not only historical and cultural resources, but abundant natural resources as well. Among these is one of the best geological and paleontological records of the Paleocene Epoch (66 to 56 million years ago) of any park in the National Park System. The Paleocene Epoch is of great scientific interest due to the great mass extinction that occurred at its opening (the Cretaceous–Paleogene extinction event), and the unusual climatic event that began at the end of the epoch (the Paleocene–Eocene Thermal Maximum, an anomalous global temperature spike). It is during the Paleocene that mammals began to diversify and move into the large-bodied niches vacated by dinosaurs. The rocks exposed at THRO preserve the latter part of the Paleocene, when mammals were proliferating and crocodiles were the largest predators. Western North Dakota was warmer and wetter with swampy forests; today these are preserved as the “petrified forests” that are one of THRO’s notable features. Despite abundant fossil resources, THRO has not historically been a scene of significant paleontological exploration. For example, the fossil forests have only had one published scientific description, and that report focused on the associated paleosols (“fossil soils”). The widespread petrified wood of the area has been known since at least the 19th century and was considered significant enough to be a tourist draw in the decades leading up to the establishment of THRO in 1947. Paleontologists occasionally collected and described fossil specimens from the park over the next few decades, but the true extent of paleontological resources was not realized until a joint North Dakota Geological Survey–NPS investigation under John Hoganson and Johnathan Campbell between 1994–1996. This survey uncovered 400 paleontological localities within the park representing a variety of plant, invertebrate, vertebrate, and trace fossils. Limited investigation and occasional collection of noteworthy specimens took place over the next two decades. In 2020, a new two-year initiative to further document the park’s paleontological resources began. This inventory, which was the basis for this report, identified another 158 fossil localities, some yielding taxa not recorded by the previous survey. Additional specimens were collected from the surface, among them a partial skeleton of a choristodere (an extinct aquatic reptile), dental material of two mammal taxa not previously recorded at THRO, and the first bird track found at the park. The inventory also provided an assessment of an area scheduled for ground-disturbing maintenance. This inventory is intended to inform future paleontological resource research, management, protection, and interpretation at THRO. THRO’s bedrock geology is dominated by two Paleocene rock formations: the Bullion Creek Formation and the overlying Sentinel Butte Formation of the Fort Union Group. Weathering of these formations has produced the distinctive banded badlands seen in THRO today. These two formations were deposited under very different conditions than the current conditions of western North Dakota. In the Paleocene, the region was warm and wet, with a landscape dominated by swamps, lakes, and rivers. Great forests now represented by petrified wood grew throughout the area. Freshwater mollusks, fish, amphibians (including giant salamanders), turtles, choristoderes, and crocodilians abounded in the ancient wetlands, while a variety of mammals representing either extinct lineages or the early forebearers of modern groups inhabited the land. There is little representation of the next 56 million years at THRO. The only evidence we have of events in the park for most of these millions of years is isolated Neogene lag deposits and terrace gravel. Quaternary surficial deposits have yielded a few fossils...