Unexploited Species Research Articles

Chromosomal characterization mediated by karyomorphological analysis and differential banding pattern in fenugreek (Trigonella foenum-graecum L.): a neglected legume

Fenugreek or Trigonella foenum-graecum L. is a commercially important yet neglected crop of the family Fabaceae, with potent medicinal applications, and can treat several diseases as well. Conventional breeding studies for higher yields of commercial crops largely depend on chromosomal information of the particular species. Despite a number of cytological research being conducted on T. foenum-graecum, a complete characterization of its chromosomes has not been achieved due to the limitations of traditional karyotype analysis methods. A range of chromosomal markers are advantageous to characterize at full extent and identify individual chromosomes rather than relying on only physical metrics. Thus, in this study, in addition to giemsa staining, other approaches like fluorochrome and silver staining were used for the precise karyomorphological analysis of this species. Enzyme maceration and air drying (EMA) based fluorochrome banding with GC-specific stain Chromomycin A3 (CMA), and AT-specific stain 4’,6-diamidino-2-phenylindole (DAPI) applied for the first time for chromosome characterization. The results showed 2n = 16 chromosomes in metaphase cells, with karyotype formula of 2m+6sm. The unique banding pattern observed in the CMA/DAPI and AgNOR staining highlights the AT and GC-rich regions as well as the nucleolar organizer regions (NORs). All this crucial information can further assist in conducting breeding studies of more precision with simultaneously encouraging similar studies that need to be done in other unexploited species of importance.

From Tasmania to the world: long and strong traditions in seaweed use, research, and development

Abstract Tasmania is an island state in south-eastern Australia that has a long and rich history of seaweed use, research, and development. It is a cool-temperate system with 750 macroalgal species currently described. Tasmanian Aboriginal peoples have lived on this land for at least 40,000 years utilising seaweed as food, shelter, water carriers and medicine, as well as for ceremonial reasons. Modern taxonomic investigations began with French naturalist Jacques-Julien Houtou de La Billardière in 1791, and there are 184 type specimens of seaweeds originating from Tasmania. Ecological and physiological studies of seaweed in Tasmania have focussed on the dominant large brown seaweeds (Laminariales and Fucales) and have contributed significantly to the global understanding of these systems, particularly related to community resilience, seaweed-urchin interactions, their habitat-forming role for other species, responses to global change, and restoration of lost habitat. Ocean warming and changing oceanography have caused a 95% decline in surface canopy cover of Macrocystis pyrifera in eastern Tasmania since the 1950s and led to a focus on restoring these lost forests. Tasmanian seaweed communities have a uniquely high proportion (up to ∼90%) of seaweeds that rely solely on CO2 for photosynthesis, which has implications for responses to ocean acidification. Tasmania has industries that use brown seaweeds for fucoidan extraction and beach-cast harvest for alginates, fertilisers, and feeds for agriculture. New aquaculture initiatives include integrated multi-trophic aquaculture, offshore kelp mariculture and Asparagopsis cultivation for bioactive products to reduce methane emissions in ruminants, as and the development of unexploited species including Caulerpa spp. for food.

Spatial variation of parrotfish assemblages at oceanic islands in the western Caribbean: evidence of indirect effects of fishing?

Fish populations that bear considerable pressure levels tend to show a decline in the average size of individuals, with the small and unexploited species replacing the large and exploited ones. It is important to carry on with their characterization in areas where they are becoming an important source of food for local human populations. An example of such species are parrotfishes, whose responses to external factors such as fishing need to be understood and predicted. In this study, we used a diver-operated stereo-video to examine individual body size, sex ratios and proportion of species of the parrotfish assemblage and analyze them on a qualitative fishing pressure gradient at four oceanic islands in the Colombian Caribbean. We reported over 10,000 occurrences of eleven parrotfish species, of which we estimated the total length of over 90%, grouping them into three size categories (large, medium, and small). Our data showed a spatial variation of parrotfishes' abundances, biomass, and individual body size. Observed differences are size-category-dependent throughout the qualitative fishing pressure. In general, the medium-bodied species had smaller sizes, lower abundances, and thus lower contribution to the total parrotfish biomass at the most heavily fished island. Unexpectedly, we found evidence of possible indirect effects over the small-bodied species Scarus iseri and Scarus taeniopterus with significantly greater abundances, and larger sizes of males of S. iseri, at the higher fishing pressure sites. Overall, our data highlights the extent of the spatial variation in the parrotfish communities at relatively short distances, and present new insights into the responses of parrotfish species on a spectrum of body sizes along a gradient of human pressure.

Double Valorization for a Discard-α-Chitin and Calcium Lactate Production from the Crab Polybius henslowii Using a Deep Eutectic Solvent Approach.

Polybius henslowii, an abundant yet unexploited species of swimming crab, was investigated as a potential source of α-chitin and calcium lactate using deep eutectic solvents (DES) as extracting solvents. Choline chloride-malonic acid (CCMA) and choline chloride-lactic acid (CCLA) were used to obtain high purity α-chitin from ball-milled P. henslowii exoskeleton in 2 h at 120 °C, with yields of 12.05 ± 2.54% and 12.8 ± 1.54%, respectively. The physical and chemical characteristics of the obtained chitins were assessed using CHN elemental analysis, attenuated total reflectance-Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Furthermore, the CCLA solvent was reusable three times with little effect on the extract purity, and calcium lactate was produced at the end of the recycling cycles. The ensuing calcium lactate was also characterized in terms of chemical and physical properties. The obtained chitin is a promising raw material for downstream processing and the double valorization pathway with the obtention of calcium salts may increase the viability of a DES-based approach for the processing of mineralized substrates.

Global decline in capacity of coral reefs to provide ecosystem services

Global decline in capacity of coral reefs to provide ecosystem services

New Method for Identifying Fungal Kingdom Enzyme Hotspots from Genome Sequences.

Fungal genome sequencing data represent an enormous pool of information for enzyme discovery. Here, we report a new approach to identify and quantitatively compare biomass-degrading capacity and diversity of fungal genomes via integrated function-family annotation of carbohydrate-active enzymes (CAZymes) encoded by the genomes. Based on analyses of 1932 fungal genomes the most potent hotspots of fungal biomass processing CAZymes are identified and ranked according to substrate degradation capacity. The analysis is achieved by a new bioinformatics approach, Conserved Unique Peptide Patterns (CUPP), providing for CAZyme-family annotation and robust prediction of molecular function followed by conversion of the CUPP output to lists of integrated “Function;Family” (e.g., EC 3.2.1.4;GH5) enzyme observations. An EC-function found in several protein families counts as different observations. Summing up such observations allows for ranking of all analyzed genome sequenced fungal species according to richness in CAZyme function diversity and degrading capacity. Identifying fungal CAZyme hotspots provides for identification of fungal species richest in cellulolytic, xylanolytic, pectinolytic, and lignin modifying enzymes. The fungal enzyme hotspots are found in fungi having very different lifestyle, ecology, physiology and substrate/host affinity. Surprisingly, most CAZyme hotspots are found in enzymatically understudied and unexploited species. In contrast, the most well-known fungal enzyme producers, from where many industrially exploited enzymes are derived, are ranking unexpectedly low. The results contribute to elucidating the evolution of fungal substrate-digestive CAZyme profiles, ecophysiology, and habitat adaptations, and expand the knowledge base for novel and improved biomass resource utilization.

Adding Value to Bycatch Fish Species Captured in the Portuguese Coast-Development of New Food Products.

We live in a world of limited biological resources and ecosystems, which are essential to feed people. Consequently, diversifying target species and considering full exploitation are essential for fishery sustainability. The present study focuses on the valorization of three low commercial value fish species (blue jack mackerel, Trachurus picturatus; black seabream, Spondyliosoma cantharus; and piper gurnard, Trigla lyra) and of two unexploited species (comber, Serranus cabrilla and boarfish, Capros aper) through the development of marine-based food products with added value. A preliminary inquiry with 155 consumers from Região de Lisboa e Vale do Tejo (Center of Portugal) was conducted to assess fish consumption, the applicability of fish product innovation, and the importance of valorizing discarded fish. Five products (black seabream ceviche, smoked blue jack mackerel pâté, dehydrated piper gurnard, fried boarfish, and comber pastries) were developed and investigated for their sensory characteristics and consumer liking by hedonic tests to 90 consumers. The most important descriptors were identified for each product (texture, flavor, color, and appearance). Comber pastries had the highest purchase intention (88%), followed by black seabream ceviche (85%) and blue jack mackerel pâté (76%). Sensory evaluations showed a clear tendency of consumers to accept reformulated products, with the introduction of the low-value and unexploited species under study.

Chemical priming agents controlling drought stress in Physalis angulata plants

Despite the use of chemical priming as a promising tool for the study of plant stress physiology and the management of field crops, little is known of its importance when studying adult plants, especially in unexploited species. The aim of this work was to evaluate the use of sodium nitroprusside (SNP), hydrogen peroxide (H2O2) and proline (Pro) as possible chemical priming inducing agents in Physalis angulata plants exposed to water deficit. For this, plants in well-watered conditions were sprayed with different concentrations of SNP (25 and 50 μM), H2O2 (10 and 20 Mm) and Pro (10 and 20 mM) and evaluated after exposure to water deficit. Although the parameters of water relations, gas exchange, growth and dry matter accumulation were reduced with the imposition of water deficit, pretreated plants showed significant improvements in the same variables. Plants sensitized with Pro and SNP doses showed improvement in relative water content and water leaf potential, contributing to the maintenance of plant water status when exposed to water deficit. The attenuation of the effects of reduced water availability on gas exchange was significantly promoted with SNP spraying, notably carbon assimilation, stomatal conductance and transpiration, parallel to an increasing in the photosynthetic pigment content. The pretreatment also influenced the growth (with Pro 10 and 20 mM; SNP 50 μM) and biomass accumulation of plants exposed to water deficit (especially with SNP 50 μM), contributing to tolerance increase to this abiotic stress. Pretreatment with hydrogen peroxide had a reduced priming effect. The pretreatment of plants with sodium nitroprusside and proline contribute to the attenuation of water deficit effects in Physalis angulata plants, acting as potential chemical priming.

CATA vs. FCP for a rapid descriptive analysis in sensory characterization of fish

AbstractStoring non‐marketable fish aboard fishing vessels takes up valuable storage space and, consequently, it is usually discarded. Therefore, the strategy to minimize the amount of discarded fish and boost the fishing economy should entail measures to turn unexploited species into marketable fish. The use of sensory descriptive analysis is usually the first step in the characterization of foods and assess their baseline appeal to the final consumer. In this study, the sensory characterization of five unexploited fish species was conducted, using a semi‐trained panel, with the objective of establishing the appeal and marketability of these species. Check‐all‐that‐apply (CATA) and Free Choice Profiling (FCP) were used to obtain descriptive attributes. Correspondence Analysis (CA) was used to examine CATA data and to compare both sensory methods, while Principal Component Analysis (PCA) was used for FCP data analysis. The results obtained with CATA method allowed to differentiate species by appearance, odor and flavor, while appearance and odor were statistically significant descriptors in FCP. CATA method was found to be more suitable to discriminate fish species, presenting a higher discriminatory power than FCP.Practical ApplicationsFor CATA and FCP methods, using a panel of tasters with short training may increase the quality of a descriptive profile by avoiding the use of less accurate descriptors and ensure that the most relevant descriptors are included, especially in the case of CATA. In this study, both methods were suitable for fish profiling, although they provide different sensory characterization for the different samples. The statistical methods applied allowed to statistically identify significant attributes for each fish species and to differentiate from each other. When comparing both tested sensory methods, CATA reveals a greater discriminatory character compared to FCP. This can be explained by the absence of a support list of descriptors in the FCP that limits the choice of attributes by the panelists.

LC–ESI–MS/MS characterization of phytochemical and enzyme inhibitory effects of different solvent extract of Symphytum anatolicum

Symphytum anatolicum Boiss., is a species belonging to the Boraginaceae family and have been used for its curative effects. This work investigated, for the first time, the bioactive compounds, the antioxidant activities and the enzyme inhibitory effects of Symphytum anatolicum roots extracts using three solvents (methanol, water and ethyl acetate). The LC–ESI–MS/MS was used to identify the individual bioactive compounds. Twenty-three biomolecules were identified in the extracts and rosmarinic acid, verbascoside, caffeic acid, chlorogenic acid and vanillin were the main identified with varied levels depending on the solvent used. Using six different assays, all extracts exhibited important antioxidant activities. Results showed also that the methanol extract exerted better tyrosinase inhibitory activities while ethyl acetate extract showed the best α-amylase inhibition. The obtained results highlighted the importance of S. anatolicum as a natural resource of bioactive compounds and encourage the use of this unexploited species for food additives, pharmaceutical industries, and skincare products.

Human overexploitation and extinction risk correlates of Chinese snakes

China is one of the countries with the richest snake biodiversity in the world. However, about one‐third of all 236 species are now considered threatened, partially due to the intense human overexploitation. Despite that, to date, no study has explicitly investigated the patterns and processes of extinction and threats of Chinese snakes, or between human exploited and unexploited snake subgroups. We addressed the following three questions: 1) which snake families proportionally include more human exploited species than expected by chance? 2) Which species traits and extrinsic factors are correlated with their extinction risk? 3) Are there differences between human exploited and unexploited species in terms of patterns and processes of extinction? We found that the family Elapidae contained a significantly higher number of exploited species. Considering eight species traits and four extrinsic factors, we performed phylogenetic correlation tests, finding that small geographic range size, large body length, oviparous reproduction, diurnal activity and high human exploitation were important in determining the extinction risk of all Chinese snakes. Moreover, human exploited snakes had a higher percentage of threatened species and large‐bodied species than unexploited snakes. Extinction risk of human exploited species was related to body length, reproduction mode and activity period, whereas that of human unexploited species were associated with geographic range size, microhabitat and annual temperature. Overall, we highlight the phylogenetic non‐random exploitation of snakes, and different factors underlying species response to human overexploitation. We suggest that conservation priority should be given to exploitation‐prone families and species with extinction‐prone traits, as identified in this study. Moreover, human exploited and unexploited species should be managed considering different strategies since their extinction risk was associated with different ecological traits. Conservation actions should also focus on preventing human threats, such as human overexploitation and habitat loss, for the effective preservation of Chinese snakes.

Jasminum nitidum – a potential unexploited jasmine species

Jasmine (Jasminum spp.) belonging to the family Oleaceae is one of the commercially significant flower crops of India. India is the largest producer of jasmine, of which 80% is being contributed by Tamil Nadu. Besides having a huge and consistent domestic market demand, jasmine flowers produced in the state are also being exported to the neighbouring countries viz., Singapore, Malaysia and Middle East countries and also to distant overseas markets including the USA. Though there is a large number of species and cultivars of jasmine, commercial cultivation is confined to only a very few, viz., Jasminum sambac, J. auriculatum, J. grandiflorum and J. multiflorum. Efforts are being taken up at Tamil Nadu Agricultural University, Coimbatore to identify potential unexploited and underexploited jasmine species for off-season flowering potential, flower yield, flower quality parameters and market preference. Evaluation of seven unexploited species viz., J. multiflorum, J. nitidum, J. calophyllum, J. flexile, J. rigidum, J. primulinum and J. arborescens indicated that five species (J. multiflorum, J. nitidum, J. calophyllum, J. flexile and J. rigidum) flower throughout the year and hence flowers of these species would be available during the lean-season or off-season of the commercial species. Among these, J. nitidum has proved as the most promising. The flower buds and open flowers of J. nitidum are attractive and comparable with those of Jathimalli (J. grandiflorum). The buds are bold and bright pink and open flowers are pure white and star shaped due to the lanceolate corolla lobes. Observation of keeping quality indicated that the buds remain unopened for 12 h under room temperature and for 60 h under cold storage at 7-8°C. The flowers possess mild fragrance and the plants are relatively free of pests and diseases. Consumer preference analysis showed that J. nitidum was on par with J. grandiflorum.

Groundfish and invertebrate community shift in coastal areas off Iceland

Biodiversity is a key concept for conservation and management and is fundamental for ecosystem-based approaches. It is of importance to consider whole areas in which communities and their ecological processes can be maintained. To effectively manage ecosystems for sustainable use and conservation, it is important to understand changes in the ecosystems. The objective of this study was to investigate the species diversity of groundfish and invertebrates, including both commercially exploited species as well as unexploited species, and identify long-term changes in the composition and abundance of the groundfish community and the northern shrimp (Pandalus borealis) in six fjords off Iceland in the period from 1995 to 2016 using data from annual shrimp survey. The results showed a strong indication of species replacement during the study period and a top-down control, where the abundance of cod and haddock increased at the same time as the abundance of northern shrimp, eelpouts, blennies and flatfish species decreased. Moreover, the increase in gadoid abundance seemed to have less effect in more open systems, which showed greater variability in species diversity and evenness compared with more closed ecosystems.

Cephalopods from the Canary Current upwelling ecosystem (Northwest Africa)

Event Abstract Back to Event Cephalopods from the Canary Current upwelling ecosystem (Northwest Africa) Amanda Luna1, 2*, Ana Ramos2, Francisco J. Rocha1 and Catalina Perales-Raya3 1 University of Vigo, Spain 2 Instituto Español de Oceanografía (IEO), Spain 3 Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Canarias, Spain Cephalopods from the Canary Current upwelling ecosystem (Northwest Africa) Luna, A. (University of Vigo, IEO Vigo), Rocha, F. (University of Vigo), Ramos, A. (IEO Vigo). The Canary Current Large Marine Ecosystem (CCLME) constitutes one of the four great marine systems of upwelling in the world, being the third in primary productivity and supporting the largest fisheries of the African coast, with an annual production of around 2-3 million tons (Valdés and Déniz-González, 2015). The cephalopod’s fauna of Northwest African region is diverse and abundant and includes species of wide distribution and elevated commercial value, among which are found squids, cuttlefish, and octopuses, whose catches in the area reach 80,000 - 120,000 tons per year. Although most of the fishery target species have been well studied, the knowledge of the unexploited species is very scarce (Rocha et al., 2017). Between 2002 and 2012 the Spanish Institute of Oceanography (IEO) and the FAO carried out eleven multidisciplinary surveys in northwest Africa, covering the shelf and continental slope from Morocco to Guinea. Quantitative data by species and important collections of benthic and pelagic cephalopods were gathered in 1334 trawl stations over the soft bottoms between 20 and 2000 m depth. Besides, oceanographic data were recorded in 1180 stations by different CTD devices. Almost 140 species have been currently identified. Among them, Sepiidae, Lolliginidae and shallow-water octopus dominate the coastal assemblages, while at the slope waters Ommastrephidae and deep‐water octopuses are more abundant. The collections and databases taken during these 11 trawl surveys represent an exceptional source of regional information on the biodiversity, composition, and distribution of cephalopod’s assemblages inhabiting North-west African continental margin. References Déniz-González, I. and Valdés, L. (2015). Introduction. In: Valdés, L. and Déniz-González, I. (eds.) Oceanographic and biological features in the Canary Current Large Marine Ecosystem. IOC-UNESCO, Paris. IOC Technical Series, 115: 19-22. Rocha, F., Fernández-Gago, R., Ramil, F. and Ramos A. (2017). Cephalopods in Mauritanian Waters. In: Ramos, A., Ramil, F. and Sanz, J.L. (eds.) Deep-sea ecosystems off Mauritania: Research of marine biodiversity and habitats in the Northwest African margin, pp. 393-418, Dordrecht, Springer. Keywords: cephalopods, Canary current, upwelling, Northwest Africa, Biodiversity Conference: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) , Braga, Portugal, 9 Sep - 12 Sep, 2019. Presentation Type: Oral Presentation Topic: Fisheries, Aquaculture and Biotechnology Citation: Luna A, Ramos A, Rocha FJ and Perales-Raya C (2019). Cephalopods from the Canary Current upwelling ecosystem (Northwest Africa). Front. Mar. Sci. Conference Abstract: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) . doi: 10.3389/conf.fmars.2019.08.00038 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 Jun 2019; Published Online: 27 Sep 2019. * Correspondence: Mx. Amanda Luna, University of Vigo, Vigo, Spain, redlunel@hotmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya Google Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya Google Scholar Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya PubMed Amanda Luna Ana Ramos Francisco J Rocha Catalina Perales-Raya Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Rapid declines across Australian fishery stocks indicate global sustainability targets will not be achieved without an expanded network of ‘no‐fishing’ reserves

Abstract A continuing debate between environmental scientists and fisheries biologists on the sustainability of fisheries management practices, and the extent of fishing impacts on marine ecosystems, is unlikely to be resolved without fishery‐independent data spanning large geographic and temporal scales. Here, we compare continental‐ and decadal‐scale trends in fisheries catches with underwater reef monitoring data for 533 sites around Australia, and find matching evidence of rapid fish‐stock declines. Regardless of a high global ranking for fisheries sustainability, catches from Australian wild fisheries decreased by 31% over the past decade. The biomass of large fishes observed on underwater transects decreased significantly over the same period on fished reefs (36% decline) and in marine park zones that allow limited fishing (18% decline), but with a negligible overall change in no‐fishing marine reserves. Populations of exploited fishes generally rose within marine reserves and declined outside the reserves, whereas unexploited species showed little difference in population trends within or outside reserves. Although changing climate and more precautionary fisheries management contribute to declining fish catches, fisheries‐independent transect data suggest that excessive fishing also plays a major role. The large number of fishery stocks that remain unmanaged or have poor data, coupled with continuing declines in the stock biomass of managed fish species, indicate that Aichi Target 6 of the Convention on Biological Diversity (i.e. ‘by 2020, all fish and invertebrate stocks and aquatic plants are managed and harvested sustainably’) will not be achieved in Australia, or elsewhere. In order to maintain some naturally functioning food webs supported by large predators and associated ecosystem services in this era of changing climate, a greatly expanded network of effective, fully protected marine protected areas is needed that encompasses global marine biodiversity. The present globally unbalanced situation, with >98% of seas open to some form of fishing, deserves immediate multinational attention.

Trends in mean growth and stability in temperate vertebrate populations

AbstractAimConsiderable controversy exists over the nature of the “Biodiversity Crisis.” While some studies suggest declining diversity, others suggest no loss on average. Population declines necessarily precede species loss and may therefore be a more sensitive metric. We examine trends in abundances to test the hypotheses: (1) losses are experienced disproportionately by some taxa, in particular amphibians; (2) positive trends in alien or unexploited species mask declines in native or exploited species, respectively; (3) populations are becoming more unstable, and variances of within‐population growth rates are increasing.LocationFreshwater and terrestrial habitats in North America and Europe.MethodsWe analysed abundances of 4,343 population time series of 983 species of temperate amphibians, birds, bony fishes, reptiles and mammals from 1970 to 2014. Population mean trends were estimated using a state‐space model to account for observation error, and then, linear mixed‐effects models were used to test mean differences among groups. As a measure of instability, trends over time in variance of population growth rates were analysed using a Breusch–Pagan test for heteroscedacity, and integrated across populations using meta‐analysis.ResultsMean trends for amphibians suggested a systematic decline, whereas birds, reptiles and mammals were increasing, on average, and freshwater fishes showed no net change in general. Origin and exploitation status did not explain the mean patterns. Large‐bodied birds and range‐restricted mammals exhibited stronger increases compared to their counterparts. For all taxonomic groups, population fluctuations have been increasing overall.Main conclusionsAddressing amphibian declines should be a priority in temperate regions. Comparatively, the lack of broad declines in the other vertebrate classes is promising and not attributable to increases in alien or non‐exploited species. Yet, caution remains warranted given that patterns of increasing variance suggested that populations are generally becoming more unstable, even in temperate, developed nations, with arguably the strongest environmental regulations.

Life history traits and exploitation affect the spatial mean-variance relationship in fish abundance.

Fishing is expected to alter the spatial heterogeneity of fishes. As an effective index to quantify spatial heterogeneity, the exponent b in Taylor's power law (V = aMb) measures how spatial variance (V) varies with changes in mean abundance (M) of a population, with larger b indicating higher spatial aggregation potential (i.e., more heterogeneity). Theory predicts b is related with life history traits, but empirical evidence is lacking. Using 50-yr spatiotemporal data from the California Current Ecosystem, we examined fishing and life history effects on Taylor's exponent by comparing spatial distributions of exploited and unexploited fishes living in the same environment. We found that unexploited species with smaller size and generation time exhibit larger b, supporting theoretical prediction. In contrast, this relationship in exploited species is much weaker, as the exponents of large exploited species were higher than unexploited species with similar traits. Our results suggest that fishing may increase spatial aggregation potential of a species, likely through degrading their size/age structure. Results of moving-window cross-correlation analyses on b vs. age structure indices (mean age and age evenness) for some exploited species corroborate our findings. Furthermore, through linking our findings to other fundamental ecological patterns (occupancy-abundance and size-abundance relationships), we provide theoretical arguments for the usefulness of monitoring the exponent b for management purposes. We propose that age/size-truncated species might have lower recovery rate in spatial occupancy, and the spatial variance-mass relationship of a species might be non-linear. Our findings provide theoretical basis explaining why fishery management strategy should be concerned with changes to the age and spatial structure of exploited fishes.

Development of sea based container culture for rearing European lobster (Homarus gammarus) around South West England

Abstract This three year field investigation consisted of three discrete experiments, examining six potential sites for rearing the European lobster (Homarus gammarus) around the Cornish coast (U.K.). Sea-based container culture (SBCC) systems were deployed, varying site, year, depth, shelter and pre-fouling, to test effects on growth and survival of juvenile H. gammarus. Site and depth were examined between May–August 2011 at two sites off the South coast. One estuarine (River Fal: RF) and one sea-based (St. Austell Bay: SA) site were assessed with containers suspended at either 2 or 8 m depth. Greatest survival was found at the SA site (56%) compared to RF (25%), with the greatest growth (specific growth rate: SGR 3%, live weight gain: LWG 0.4 g and carapace length gain: CLG 4.5 mm) also achieved at SA. Depth did not affect juvenile development. Between May and August 2012, one estuarine (Fowey: F) and two sea-based (SA and St. Mawes: SM) sites on the south coast were selected to assess the effect of site and shelter. SM showed the highest survival (93%). Growth and survival were not affected by the presence of a shelter. From August to December 2013, three sites off the north and south coasts were selected to assess the effect of site, depth, pre-fouling and feed availability. Sea-based (Port Quin Bay: PQ, Wave Hub: WH and SA) sites were assessed, with containers submerged at either 3 or 10 m above the sea bed (PQ 7–14 m, WH 42–49 m depth at chart datum). Survival did not significantly differ between sites (61–86%), but growth at the PQ site (LWG 0.7 g; carapace length gain: CLG 6.1 mm) was significantly greater than at all other sites (LWG 0.3–0.4 g; CLG 2.5–3.6 mm). Depth did not affect juvenile development. Pre-fouling reduced growth at all sites. Feed availability varied between sites with PQ showing the greatest taxonomical units. Variations between years were also shown between 2011 and 2013 at the SA site. SBCC systems show potential for culturing H. gammarus juveniles compared to hatchery controls (survival ≤ 46%), acting as a transition step between hatchery rearing and release for stocking purposes. The importance of site selection and between year variations is highlighted as important factors to consider for larger scale assessment of aquaculture potential. Statement of relevance This work presents the culmination of three discrete studies between 2011 and 2013 that investigated the use of sea based container culture (SBCC) systems for rearing European lobster (H. gammarus) juveniles at various sites around South West England. This is a relatively novel field and the first study of its kind to consider sites around the South West of England and also to quantitatively assess potential feed species. The main findings of this work identify the importance of site selection, deployment and container structure. With an ever increasing demand for protein, there needs to be efforts to relieve pressure on natural fishing stocks. This study not only highlights the potential for SBCC to provide improved stock enhancement processes but also discusses the potential for aquaculture of this currently unexploited species. Juvenile culture is one of the bottlenecks for the development of lobster culture due to high unit cost of production, high mortality rates due to cannibalism within intensive culture systems and long development times, and as such we feel that this work is extremely timely and relevant. This manuscript will not only contribute to the understanding of how SBCC systems can be employed, but also adds to our understanding of the requirements of the species. Therefore, this work is of significant interest to those involved in the culture of lobsters and marine animals generally.

Food‐web patterns and diversity in tropical fish communities

The food webs for three Sri Lankan reservoirs, Minneriya (ancient and shallow), Udawalawe (young and shallow) and Victoria (young and deep), were compared. The species richness of the fish communities was highest in Minneriya (30 species), intermediate in Udawalawe (21 species) and lowest in Victoria (18 species). The fish species belonged to 11 families, with Cyprinidae dominating the community in terms of both abundance and species richness. The daily quantity of food consumed per fish species was used to distinguish weak from strong trophic interactions in these food webs. The fish community consumption pattern was characterized by a few strong interactions and many weak ones. The number of major consumers (i.e. contributing >5% of the total fish community consumption) for each reservoir was small and similar for all three reservoirs. Dawkinsia singhala and Amblypharyngodon melettinus were the two major consumers in all three reservoir food webs. Puntius chola was a major consumer in Minneriya and Victoria, although not in Udawalawe, where it fed less on detritus than for the other two food webs. The fish community fed mainly at the bottom of the food web, primarily on algae, macrophytes and detritus in all three reservoirs, with very little piscivory occurring. The average food-web length was measured as the mean trophic index weighted for the consumption rates of the various fish populations that together comprised the fish community. The average food-web length in these three Sri Lankan reservoirs relatively short, compared with most other tropical lake/reservoir food webs in Asia and Africa for which relevant data were available. Furthermore, traditionally unexploited species (Oreochromis mossambicus; O. niloticus), in contrast to species of commercial fisheries interest, are major role players in the trophic dynamics of reservoir ecosystems. Thus, based on this study, the potential of their exploitation should be considered in the management of reservoir fisheries.

Marine reserves: Fish life history and ecological traits matter

Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.