40 research outputs found
Using Seafood Traceability to Teach the Complexities of Natural Resource Management and Sustainability
This lesson plan addresses the challenge of conveying to students the globalized nature and complexity of natural resource management. Specifically, it uses seafood traceability, or the ability to track seafood as it moves through the global seafood supply chain, as a theme for understanding the potential for science and technological innovations to enable traceability as well as the different roles that various stakeholders play in ensuring fisheries sustainability. The lesson plan conveys several themes related to environmental sustainability including: the role of consumer empowerment, the importance of data and information sharing, the need to coordinate multiple stakeholders, and the intersection of science, technology, and policy- making. In one classroom activity, students are guided through a small-group, active-learning exercise that challenges them to make sustainable seafood choices from a restaurant menu. In another activity, students are asked to role-play and consider the information needs of various stakeholders in the seafood supply chain. Overall, the lesson plan is designed to demonstrate that there is no one single solution to realize seafood traceability and ensure fisheries sustainability. Instead, fisheries and natural resource management require multifaceted solutions and the involvement of multiple sectors of society
Local Biomass Baselines and the Recovery Potential for Hawaiian Coral Reef Fish Communities:Hawaiian Reef Fish Recovery Potential
Catch Composition and Selectivity of Fishing Gears in a Multi-Species Indonesian Coral Reef Fishery
There are millions of small-scale fishers worldwide that rely on coral reefs for their livelihood. Yields from many of these coral reef fisheries, however, have been declining. In Indonesia and other coral reefs worldwide, management approaches are dominated by marine protected areas but other options including gear-restrictions may be feasible and more adaptive to local ecological and social conditions. Yet, there is little data on the impacts and selectivity of fishing gears for coral reef fisheries. In this paper, we present results from a case study on the island of Lombok, where we examine the selectivity and overlap in catch composition of the two main fishing gear types: spearguns and handlines. The catch per unit effort (CPUE) was greater in handlines than spearguns, 10.8 and 9.97 kg trip-1, respectively. The two gears targeted different fish communities with little overlap in dominant species, suggesting a partitioning of resources; handlines targeted piscivores, whereas spearguns targeted mostly herbivores. Mean trophic level was 3.6 for the handline catch and 2.8 for spearguns, where it was inversely related to CPUE. Spearguns captured more species overall and the number of species increased as the CPUE increased. Length parameters of maturity indicated that neither gear showed signs of (growth) overfishing and fishing grounds dominated by speargun fishers had catches associated with younger ages at first maturity than handlines. Our findings provide local baseline data on the potential utility of gear restrictions as a management tool. Specifically, managers could monitor reefs and reduce handlines when piscivorous fishes are low and on spearguns when species diversity is low or algal abundance is high. Should it become more desirable to implement ecosystem approaches to management that are adaptive to changing ecological and social conditions, these indicators may be used as starting points along with local management preferences of fishers
Environmental performance of blue foods
Fish and other aquatic foods (blue foods) present an opportunity for more sustainable diets1,2. Yet comprehensive comparison has been limited due to sparse inclusion of blue foods in environmental impact studies3,4 relative to the vast diversity of production5. Here we provide standardized estimates of greenhouse gas, nitrogen, phosphorus, freshwater and land stressors for species groups covering nearly three quarters of global production. We find that across all blue foods, farmed bivalves and seaweeds generate the lowest stressors. Capture fisheries predominantly generate greenhouse gas emissions, with small pelagic fishes generating lower emissions than all fed aquaculture, but flatfish and crustaceans generating the highest. Among farmed finfish and crustaceans, silver and bighead carps have the lowest greenhouse gas, nitrogen and phosphorus emissions, but highest water use, while farmed salmon and trout use the least land and water. Finally, we model intervention scenarios and find improving feed conversion ratios reduces stressors across all fed groups, increasing fish yield reduces land and water use by up to half, and optimizing gears reduces capture fishery emissions by more than half for some groups. Collectively, our analysis identifies high-performing blue foods, highlights opportunities to improve environmental performance, advances data-poor environmental assessments, and informs sustainable diets
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Rights and representation support justice across aquatic food systems
Injustices are prevalent in food systems, where the accumulation of vast wealth is possible for a few, yet one in ten people remain hungry. Here, for 194 countries we combine aquatic food production, distribution and consumption data with corresponding national policy documents and, drawing on theories of social justice, explore whether barriers to participation explain unequal distributions of benefits. Using Bayesian models, we find economic and political barriers are associated with lower wealth-based benefits; countries produce and consume less when wealth, formal education and voice and accountability are lacking. In contrast, social barriers are associated with lower welfare-based benefits; aquatic foods are less affordable where gender inequality is greater. Our analyses of policy documents reveal a frequent failure to address political and gender-based barriers. However, policies linked to more just food system outcomes centre principles of human rights, specify inclusive decision-making processes and identify and challenge drivers of injustice
Why study just one reef : spatial patterns of environmental heterogeneity and genetic relatedness for the coral, Pocillopora damicornis
Ph.D. University of Hawaii at Manoa 2013.Includes bibliographical references.In molecular ecology, researchers often test for a pattern of isolation-by-distance, whereby genetic variants sampled closer together in space are, on average, found to be more genetically related than variants sampled at further distances. Such a pattern can be explained by dispersal processes, whereby the genetic homogenizing effects of migration are distance-limited. Several examples from the marine environment, however, do not fit this expectation (Selkoe et al. 2010), either because the patterns are anisotropic (i.e., geographically asymmetric) or stochastic, leading researchers to give ad hoc explanations for the paradoxical pattern. For corals, in particular, geographic patterns of genetic variation have often proven difficult to interpret (Adjeroud & Tsuchiya 1999; Ayre & Hughes 2000; Magalon et al. 2005; Baums et al. 2006; Severance & Karl 2006; Souter et al. 2009). The interest of this dissertation is to gain insight into this coral population genetic paradox.
The original paradigm of dispersal in the sea was one of demographically open populations connected by planktonic larvae capable of dispersing long-distances across open ocean. Subsequent genetic studies, however, uncovered genetic differentiation on much smaller than expected scales. In fact, for corals, several studies demonstrate the potential for adaptive genetic variation (e.g., D'Croz & Maté 2004; Vermeij et al. 2007).
Barshis et al. 2010). Corals also share several terrestrial plant-like characteristics (e.g., dispersing propagule stage, sessile adult stage, and the ability to reproduce clonally) that are also believed to enhance the adaptive capacities of plants to small-scale environmental heterogeneity (Vekemans & Hardy 2004). Taken together, these observations warrant the study of coral genetic and environmental variation on an intrareef scale, a scale for which there has been little interest. In ecology, it is widely recognized that patterns are scale-dependent. Population genetic sampling designs, however, rarely bridge across scales and have only recently been subject to explicitly spatial analyses whereby the spatial coordinates of individual sampling units are examined alongside genetic data (Storfer et al. 2007). Thus, taking a landscape-genetics approach, combining spatial analysis with landscape ecology and population genetics, will be important for making inferences on the processes driving patterns of genetic variation on an intra-reef scale.
The dataset for this dissertation is a near-exhaustive assessment of individual-level spatial genetic patterns for the widely-studied, cosmopolitan, pan-Pacific coral, Pocillopora damicornis within a single coral reef as well as a reef-wide characterization of environmental heterogeneity. The focal study site, Reef 19, is a single patch reef (diameter of ~40 m) in Kāne'ohe Bay (21.45767°N, 157.80677°W) with a depth of between 1 and 5 m. Using a two year temperature dataset taken across a 4 m grid, Chapter 2 describes the environmental heterogeneity of Reef 19 in terms of temperature, depth, and habitat cover (Gorospe & Karl 2011). Chapter 3 (Gorospe & Karl, accepted) introduces the genetic and spatial data for P. damicornis, with an interest in dispersal and colonization on this scale. These data included a near-exhaustive (n=2352) genetic sampling and spatial mapping of P. damicornis throughout Reef 19, as well as a much smaller, stratified random sampling effort on three neighboring reefs. Rarely, however, is it practical to sample so intensively. Thus, the consequences of sampling effort and design on the characterization of reef genetic diversity are explored in Chapter 4. Finally, in Chapter 5, environmental, genetic, and spatial data are combined in a landscape genetics approach to tease apart the influence of spatially-versus environmentally mediated processes on intra-reef patterns of genetic variation. Throughout, results are discussed from the perspective of P. damicornis' breadth of literature, within the framework of the coral population genetics paradox described above, as well as within the context of global climate change and coral reef conservation
SPAGeDi_Reef19_completegenospace
Input file for the program, Spatial Pattern Analysis of Genetic Diversity (SPAGeDi; Hardy and Vekemans 2002) giving spatial and multi-locus genetic data for Reef 19, the focal reef of our study where Pocillopora damicornis was near-exhaustively surveyed. From left to right, columns represent Sample ID Number, x coordinate, y coordinate, and genotypes at each of 6 microsatellite loci
Data from: Genetic relatedness does not retain spatial pattern across multiple spatial scales: dispersal and colonization in the coral, Pocillopora damicornis
Patterns of isolation-by-distance are uncommon in coral populations. Here, we depart from historical trends of large-scale, geographic genetic analyses by scaling down to a single patch reef in Kāne‘ohe Bay, Hawai‘i, and map and genotype all colonies of the coral, Pocillopora damicornis. Six polymorphic microsatellite loci were used to assess population genetic and clonal structure and to calculate individual colony pairwise relatedness values. Our results point to an inbred, highly clonal reef (between 53 and 116 clonal lineages out of 2352 genotyped colonies) with a very skewed genet frequency distribution (over 70% of the reef was composed of just seven genotypes). Spatial autocorrelation analyses revealed that corals found close together on the reef were more genetically related than corals further apart. Spatial genetic structure disappears, however, as spatial scale increases and then becomes negative at the largest distances. Stratified, random sampling of three neighbouring reefs confirms that reefs are demographically open and inter-reef genetic structuring was not detected. Attributing process to pattern in corals is complicated by their mixed reproductive strategies. Separate autocorrelation analyses, however, show that the spatial distribution of both clones and non-clones contribute to spatial genetic structure. Overall, we demonstrate genetic structure on an intra-reef scale and genetic panmixia on an inter-reef scale indicating that, for P. damicornis, small- and large-scale dispersal processes are likely not the same. By starting from an inter-individual, intra-reef level before scaling up to an inter-reef level, this study demonstrates that isolation-by-distance patterns for the coral P. damicornis are limited to small scales and highlights the importance of investigating genetic patterns and ecological processes at multiple scales
Small-Scale Spatial Analysis of In Situ Sea Temperature throughout a Single Coral Patch Reef
Thermal stress can cause geographically widespread bleaching events, during which corals become decoupled from their symbiotic algae. Bleaching, however, also can occur on smaller, spatially patchy scales, with corals on the same reef exhibiting varying bleaching responses. Thus, to investigate fine spatial scale sea temperature variation, temperature loggers were deployed on a 4 m grid on a patch reef in Kāne'ohe Bay, Oahu, Hawai‘i to monitor in situ, benthic temperature every 50 minutes at 85 locations for two years. Temperature variation on the reef was characterized using several summary indices related to coral thermal stress. Results show that stable, biologically significant temperature variation indeed exists at small scales and that depth, relative water flow, and substrate cover and type were not significant drivers of this variation. Instead, finer spatial and temporal scale advection processes at the benthic boundary layer are likely responsible. The implications for coral ecology and conservation are discussed
Data from: Depth as an organizing force in Pocillopora damicornis: intra-reef genetic architecture
Relative to terrestrial plants, and despite similarities in life history characteristics, the potential for corals to exhibit intra-reef local adaptation in the form of genetic differentiation along an environmental gradient has received little attention. The potential for natural selection to act on such small scales is likely increased by the ability of coral larval dispersal and settlement to be influenced by environmental cues. Here, we combine genetic, spatial, and environmental data for a single patch reef in Kāne‘ohe Bay, O‘ahu, Hawai‘i, USA in a landscape genetics framework to uncover environmental drivers of intra-reef genetic structuring. The genetic dataset consists of near-exhaustive sampling (n = 2352) of the coral, Pocillopora damicornis at our study site and six microsatellite genotypes. In addition, three environmental parameters – depth and two depth-independent temperature indices – were collected on a 4 m grid across 85 locations throughout the reef. We use ordinary kriging to spatially interpolate our environmental data and estimate the three environmental parameters for each colony. Partial Mantel tests indicate a significant correlation between genetic relatedness and depth while controlling for space. These results are also supported by multi-model inference. Furthermore, spatial Principle Component Analysis indicates a statistically significant genetic cline along a depth gradient. Binning the genetic dataset based on size-class revealed that the correlation between genetic relatedness and depth was significant for new recruits and increased for larger size classes, suggesting a possible role of larval habitat selection as well as selective mortality in structuring intra-reef genetic diversity. That both pre- and post-recruitment processes may be involved points to the adaptive role of larval habitat selection in increasing adult survival. The conservation importance of uncovering intra-reef patterns of genetic diversity is discussed