Territorial use rights in fisheries (TURFs) represent a form of spatial co-management to secure access rights for communities while simultaneously supporting marine conservation. In Ecuador, a TURF system emerged in many mangrove-associated fisheries after the government enacted legislation in 1999 favoring decentralized mangrove conservation. In communities where custodias (mangrove concessions) were implemented, members of local fishing associations have defined access privileges for certain fisheries within the boundaries of their concession. The present study explores the tradeoffs that emerged through the interaction between informal customary norms in fishing and the formal TURF system associated with custodias. Combining fishery data and ethnographic insights about Ecuador's fishery for mangrove cockles Anadara tuberculosa (G. B. Sowerby I, 1833) and Anadara similis (C. B. Adams, 1852), I evaluate outcomes of fisher empowerment, perceptions of success, fishery productivity, and tradeoffs. I argue that empowering fishers with stewardship rights is critical for successful TURFs in Ecuador. Custodias have strengthened access rights and created conditions that promote habitat health with implications for fishery productivity and economic benefits derived from larger catch and shell sizes. On the other hand, custodias limit access and fisher mobility, resulting in the reconfiguration of fishing space and displacement of independent fishers from their customary grounds. Moreover, secure access rights do not necessarily provide incentives for individuals to harvest shells according to the size regulations imposed by current policies. Understanding the benefits and limitations of this integrated approach to coastal management may provide valuable insights for other forms of spatially-explicit marine governance and fisheries co-management.
There is a growing interest in working with customary management (CM) systems to effectively manage benthic resources and small-scale fisheries. The underlying notion is that CM institution as territorial use rights in fisheries (TURFs) can be sufficiently adaptive and dynamic to create the local incentives that are necessary for promoting sustainable fishing practices and marine conservation more generally in a given region. This paper reviews the social opportunities and challenges of working with CM systems as a form of TURF, particularly in Oceania. A key conclusion is that policy makers and managers not only need to recognize natural interconnectivity in any one marine space, but also consider the social interconnectivity of stakeholders that covers customary TURFs. Only by recognizing and working with the existing social networks that overlay any given marine territory can the operational principles of CM (as reviewed in this paper) be effectively deployed for achieving some kind of bioeconomic efficiency and creating an equitable rights-based fisheries management system.
Unsustainable fishing in marine systems creates fisheries management and conservation challenges, with implications for ecosystem health, livelihoods, economies, and seafood supply. Thus there is a need for management approaches that can support productive fisheries and healthy ecosystems. Property rights, and particularly spatial rights or territorial use rights in fisheries (TURFs), are increasingly proposed as a solution. It has been suggested that TURFs may align fishers' incentives with long-term stewardship, resulting in improved yields and positive conservation outcomes. Here we examined this idea by reviewing existing theoretical and empirical evidence for TURF performance in achieving both fisheries and conservation goals, and find equivocal evidence that TURFs can consistently deliver on this promise. We then explored the potential to improve outcomes by implementing no-take marine reserves with TURFs ("TURF-reserves"). We evaluated theoretical and empirical evidence in the literature and develop a simulation model to examine tradeoffs for achieving conservation and fishery objectives. With our model, we examined different management regimes (e.g., open access vs TURFs), harvest controls within the TURF (e.g., selectivity and harvest rate restrictions), and varying reserve sizes. We found that combining reserves with TURFs does not eliminate the tradeoff between fisheries and conservation goals if the TURF already effectively controls fishing pressure. However, given the results from our literature review, many TURFs may not achieve effective fisheries management. Thus, TURF-reserves may be better able to balance fisheries and conservation goals relative to TURF-only systems, but outcomes will depend on target species mobility, TURF size, and fishing intensity outside the TURF-reserve.
Selective fisheries may impact non-target species as well as limit the productivity of target species if their predators are not harvested. The outcomes of multispecies harvest strategies that include targeting predators depend on ecological and economic constraints, though the development of ecosystem-based management plans has typically focused on ecological constraints.
In Chignik, Alaska, sockeye salmon support a valuable commercial fishery and, as juveniles, are preyed upon by coho salmon, a species not subject to a targeted harvest. Whether exploitation of coho salmon would enhance overall fishery value by releasing sockeye salmon from predation constraints is not understood. We employ simulation models to examine the ecological and economic conditions necessary for directly targeting coho salmon to benefit fishers and seafood processors, two distinct but inter-dependent stakeholders in this ecosystem.
Model results indicate fishers are likely to experience increased value regardless of economic constraints, as long as coho salmon predation negatively affects sockeye salmon productivity. However, seafood processors are much more limited in the conditions which produce increased economic value, constrained by greater operation costs required to process harvested coho salmon.
Synthesis and applications. The unique economic constraints and opportunities of different stakeholders can present contrasting outlooks on the potential benefits of alternative harvest strategies, even if the alternative strategies are predicted to increase yield. The findings herein demonstrate the importance of considering multiple stakeholders when considering alternative management strategies. Depending on the level of risk stakeholders are willing to accept, an active adaptive management strategy reducing coho salmon escapement to low levels could provide valuable information about ecosystem structure as well as potentially providing the greatest economic benefit to the fishery.
It is often assumed that issue advocacy will compromise the credibility of scientists. We conducted a randomized controlled experiment to test public reactions to six different advocacy statements made by a scientist—ranging from a purely informational statement to an endorsement of specific policies. We found that perceived credibility of the communicating scientist was uniformly high in five of the six message conditions, suffering only when he advocated for a specific policy—building more nuclear power plants (although credibility did not suffer when advocating for a different specific policy—carbon dioxide limits at power plants). We also found no significant differences in trust in the broader climate science community between the six message conditions. Our results suggest that climate scientists who wish to engage in certain forms of advocacy have considerable latitude to do so without risking harm to their credibility, or the credibility of the scientific community.
In 2016, countries began meeting at the United Nations (UN) to prepare for negotiations to develop an international legally binding instrument on the conservation and sustainable use of marine biological diversity in areas beyond national jurisdiction (ABNJ). How the instrument will relate to submarine cables, if at all, remains to be decided. The preparatory committee will address a “package” of issues, among them the application of area-based management tools, including marine protected areas (MPAs) and environmental impact assessments (EIAs) to activities in ABNJ. EIAs and MPAs already affect submarine cable operations in national jurisdictions. In ABNJ, a new instrument should formalize a cooperative framework with the cable industry to provide limited environmental management where necessary without over-burdening cable operations. This approach would be consistent with the UN Convention on the Law of the Sea and could also inform governance with respect to other activities likely to be benign in ABNJ.
Understanding range limits is critical to predicting species responses to climate change. Subtropical environments, where many species overlap at their range margins, are cooler, more light-limited and variable than tropical environments. It is thus likely that species respond variably to these multi-stressor regimes and that factors other than mean climatic conditions drive biodiversity patterns. Here, we tested these hypotheses for scleractinian corals at their high-latitude range limits in eastern Australia and investigated the role of mean climatic conditions and of parameters linked to abiotic stress in explaining the distribution and abundance of different groups of species. We found that environmental drivers varied among taxa and were predominantly linked to abiotic stress. The distribution and abundance of tropical species and gradients in species richness (alpha diversity) and turnover (beta diversity) were best explained by light limitation, whereas minimum temperatures and temperature fluctuations best explained gradients in subtropical species, species nestedness and functional diversity. Variation in community structure (considering species composition and abundance) was most closely linked to the combined thermal and light regime. Our study demonstrates the role of abiotic stress in controlling the distribution of species towards their high-latitude range limits and suggests that, at biogeographic transition zones, robust predictions of the impacts of climate change require approaches that account for various aspects of physiological stress and for species abundances and characteristics. These findings support the hypothesis that abiotic stress controls high-latitude range limits and caution that projections solely based on mean temperature could underestimate species’ vulnerabilities to climate change.
Atlantic salmon (Salmo salar) is currently the highest valued species grown in Europe. The industry has been on the frontline of public concerns regarding sustainability which has increased the use of recirculating aquaculture systems (RAS). Salmon has changed from a luxury product to global commodity. Nevertheless, food products need to meet consumers demand for the industry to be successful. Descriptive sensory tests present a sophisticated tool for the comparison of product prototypes to understand consumer responses in relation to sensory attributes. Aquaculture is being promoted in the Basque region with the aim of creating a sustainable and complementary economic activity to the fishing and seafood sectors. Here, RAS and salmon have been prioritized as a potential technology and species respectively. Both salmon's growth and a hedonic evaluation of the final product's consumer acceptance and purchasing intention were studied. One thousand five hundred salmon individuals were grown for 497 days at two different thermal regimes in two pilot-scale RAS units using partial reuse water recirculation systems. Growth rates were significantly different for both temperature regimes during the second summer season; some compensatory growth patterns were observed that followed the timing of the natural thermal regime. No significant differences were observed at sensorial level between fillet samples from the present study and salmon from Denmark. Consumer's high level of acceptance and positive product purchasing intention reflect the possibility of locally marketing RAS grown salmon. This study refers to the first technical attempt at salmon in land-based aquaculture systems in northern Spain.
Minimizing illegal fishing is of paramount importance for fisheries sustainability. The present study focused on the fisheries infringements through the analysis of the official records in one of the largest Mediterranean lagoons, Mesolonghi-Etolikon, and the analysis of questionnaires answered by local fishermen to determine the true effectiveness of the control efforts. This double analysis represents a valuable case study for determining illegal fisheries practices, status of control, and efficacy of regulations. Results exhibited that: (a) the high contribution of the recorded infringements was due to absence of fishermen/vessel licenses, (b) fines are not proportionate with the type of illegal activity, and (c) the number of the recorded infringements represented a very small percentage of the estimated number of fishing days conducted by both professional fishermen and people not having fishing/vessel license. Findings indicated a situation with great presence of illegality that might completely weak any possibility for assessing the status of fisheries and resources and seriously hamper any definition of thresholds useful for sustainable management. Solutions are discussed especially in the light of revision of regulations and of transparency in the decision-making process.
Corals on the reef corridor of the southwestern Gulf of Mexico have evolved on a terrigenous shallow continental shelf under the influence of several natural river systems. As a result, water turbidity on these reefs can be high, with visibility as low as < 1 m, depending on reef location and season. Using a presence-absence species database from field surveys, literature search, and satellite data on sea surface temperature, turbidity and chlorophyll-a, the coral species composition and environmental variables were analyzed for the three main reef systems of the reef corridor of the southwestern Gulf of Mexico. Completeness of the data set was assessed using species accumulation curves and non-parametric estimators of species richness. Differences in coral assemblages’ composition between the reef systems were investigated using univariate (ANOVA) and multivariate (nMDS, ANOSIM, SIMPER) analyses and the relationship between the assemblages and environmental data was assessed using a forward selection process in canonical correspondence analysis (CCA) to eliminate non-significant environmental variables. The northern and central Veracruz reef systems share a similar number of coral species (p= 0.78 mult. comp.) and both showed higher species richness than the southern system (p< 0.001 mult. comp.). In terms of the assemblages’ structure, significant differences were found (ANOSIM R= 0.3, p= 0.001) with larger average dissimilitude between north-south (75.4% SIMPER) and central-south (74.2%) than north-central (27%) comparisons. Only environmental variables related to water turbidity and productivity were significant on the final CCA configuration, which showed a gradient of increasing turbidity from north to south. Reef geomorphology and the effect of turbidity help explain differences in coral assemblages’ composition. More studies are necessary to establish if turbidity could function as a refuge for future environmental stress. Each Veracruz reef system is at the same time unique and shares a pool of coral species. To protect these ecosystems it is necessary to effectively manage water quality and consider coral diversity on the reef corridor of the southwestern Gulf of Mexico.
Due to the ambiguity of international law in this area, taking action against vessels without nationality on the high seas has been inherently problematic. In recent years, however, a number of legal developments have emerged in the international fisheries sphere, designed to address this uncertainty. This article considers the ambiguity in this area, describes recent legal developments and contemplates their impact on the law, including their potential to contribute to the development of a new customary norm, or represent evidence of an international legal and political consensus on existing law. It considers the likelihood that these recent developments, whatever their precise legal effect, will facilitate the international community’s efforts in combatting illegal, unreported and unregulated fishing into the future.
Gulls were assessed as sentinels of contamination in the coastal zone of the Southern Baltic, research material being obtained from dead birds collected on Polish beaches and near fishing ports in 2009–2012. In feathers and blood of four gull species: herring gull (Larus argentatus), common gull (Larus canus), black-headed gull (Chroicocephalus ridibundus), and great black-backed gull (Larus marinus), concentration of total mercury (HgT) was assayed, taking into account the type of feathers, sex, and age. Stable isotopes (δ15N, δ13C) were used as tracers of trophic position in the food web. In the study, feathers and blood were compared as non-invasive indicators of alimentary exposure introducing mercury into the system. In order to do that, the correlations between mercury concentrations in the blood, feathers, and the birds’ internal tissues were examined. The strongest relations were observed in the liver for each species R2Common Gull = 0.94, p = 0.001; R2Black-headed Gull = 0.89, p = 0.001; R2Great Black-backed Gull = 0.53, p = 0.001; R2Herring Gull = 0.78, p = 0.001. While no correlation was found with feathers, only developing feathers of juvenile herring gulls were found to be a good indicator immediate of exposure through food (R2muscle = 0.71, p = 0.001; R2kidneys = 0.73, p = 0.001; R2heart = 0.89, p = 0.001; R2lungs = 0.86, p = 0.001; R2brain = 0.83, p = 0.001). Additionally, based on studies of herring gull primary feathers, decrease of mercury concentration in the diet of birds over the last two decades is also discussed.
Regional fisheries management organizations (RFMOs) addressing the management of living marine resources have a long history, beginning in 1811 with the North Pacific Fur Seal Convention followed by the International Pacific Halibut Convention in 1924. Following the expansion of fisheries after WWII, RFMOs proliferated and after the general acceptance of a 200 mile extended jurisdiction in the mid- 1970s many more nations became involved. There are approximately 17 RFMOs (depending on the definition of “management”) of the over 40 marine Regional Fisheries Bodies (RFBs) identified by the Food and Agriculture Organization (FAO) of the United Nations. The Large Marine Ecosystem (LME) approach has roots in the experience of the International Commission for the Conservation of Northwest Atlantic Fisheries (now defunct and replaced by the Northwest Atlantic Fisheries Organization (NAFO)) which pioneered ecosystem based fisheries management. The LME approach to the assessment of coastal ocean goods and services was included in the operational guidelines for project proposals by the International Waters Focal Area of the Global Environmental Facility (GEF) in 1995. LMEs have fisheries as one of five major components to be addressed under the modular assessment and management framework for LME project development. As LME Programs enter the stage where they need to move to develop their governance responsibilities, the relationship with existing RFMOs is critical. This paper examines possibilities for this interaction with special attention to Latin American and Caribbean LMEs particularly in relation to their three northeastern LMEs. Possible inferences from the experiences of the coastal states of the US are also addressed, considering the Gulf and Atlantic States Marine Fisheries Commissions as a pseudo RFMO with the states assuming a role similar to countries.
The Paranaguá Estuarine Complex (PEC), Paraná State, southern Brazil, has rich biodiversity and attracts the attention of researchers in several areas. In this region, there is a mosaic of protected areas that aim to maintain the natural heritage through regulation of the use of the area and natural resources and are also home to traditional extractive communities, such as fisherfolk. These coastal communities are dependent on local resources and are continually in contact with researchers working mainly on studies related to coastal environmental issues. However, the results generated in these studies realized in marine environment are rarely shared or discussed with these traditional communities before being taken to decision makers, which can result in conflicts between those involved, the acceptance of reduced management measures and the loss of research credibility. The objective of this article is to describe the perception of marine traditional fishermen from the village of Ilha das Peças (VIP) and the village of Ilha do Superagui (VIS), both located in the vicinity of the protected areas, regarding the scientific research conducted in the PEC. In 2012, ethnographic interviews were conducted through semi-structured questionnaires given to fisherfolk in the VIP (n = 40) and the VIS (n = 50). The level of education among the fishermen in the two villages is low, which can influence the perception of the research conducted in the region. All respondents in the VIP and VIS described not receiving reports from researchers regarding the results. Therefore, there is a feeling of dissatisfaction regarding the lines of research in general, which is extended to the funding agencies and the presence of researchers in the area, representing conflicts with the management of marine resources. According to the respondents, the research does not seek solutions to social and environmental problems but only evaluates and seeks to preserve the fauna and flora, excluding the human component of the broader ecological processes. Dialogue between scientific and traditional knowledge is essential in the joint search for effective solutions to social and environmental problems, especially in areas designated as priorities for biological conservation in the coastal environment.
A new approach is presented for analysis of microplastics in environmental samples, based on selective fluorescent staining using Nile Red (NR), followed by density-based extraction and filtration. The dye adsorbs onto plastic surfaces and renders them fluorescent when irradiated with blue light. Fluorescence emission is detected using simple photography through an orange filter. Image-analysis allows fluorescent particles to be identified and counted. Magnified images can be recorded and tiled to cover the whole filter area, allowing particles down to a few micrometres to be detected. The solvatochromic nature of Nile Red also offers the possibility of plastic categorisation based on surface polarity characteristics of identified particles. This article details the development of this staining method and its initial cross-validation by comparison with infrared (IR) microscopy. Microplastics of different sizes could be detected and counted in marine sediment samples. The fluorescence staining identified the same particles as those found by scanning a filter area with IR-microscopy.
Marine debris is a burgeoning global issue with economic, ecological and aesthetic impacts. While there are many studies now addressing this topic, the influence of urbanisation factors such as local population density, stormwater drains and roads on the distribution of coastal litter remains poorly understood. To address this knowledge gap, we carried out standardized surveys at 224 transect surveys at 67 sites in two estuaries and along the open coast in Tasmania, Australia. We explored the relative support for three hypotheses regarding the sources of the debris; direct deposition by beachgoers, transport from surrounding areas via storm water drains and coastal runoff, and onshore transport from the marine system. We found strong support for all three mechanisms, however, onshore transport from the marine reservoir was the most important mechanism. Overall, the three models together explained 45.8 percent of the variation in our observations. Our results also suggest that most debris released into the marine environment is deposited locally, which may be the answer to where all the missing plastic is in the ocean. Furthermore, local interventions are likely to be most effective in reducing land-based inputs into the ocean.
During 2015–2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.
Bacterial and archaeal communities inhabiting the subsurface seabed live under strong energy limitation and have growth rates that are orders of magnitude slower than laboratory-grown cultures. It is not understood how subsurface microbial communities are assembled and whether populations undergo adaptive evolution or accumulate mutations as a result of impaired DNA repair under such energy-limited conditions. Here we use amplicon sequencing to explore changes of microbial communities during burial and isolation from the surface to the >5,000-y-old subsurface of marine sediment and identify a small core set of mostly uncultured bacteria and archaea that is present throughout the sediment column. These persisting populations constitute a small fraction of the entire community at the surface but become predominant in the subsurface. We followed patterns of genome diversity with depth in four dominant lineages of the persisting populations by mapping metagenomic sequence reads onto single-cell genomes. Nucleotide sequence diversity was uniformly low and did not change with age and depth of the sediment. Likewise, there was no detectable change in mutation rates and efficacy of selection. Our results indicate that subsurface microbial communities predominantly assemble by selective survival of taxa able to persist under extreme energy limitation.
Failure to stem trends of ecological disruption and associated loss of ecosystem services worldwide is partly due to the inadequate integration of the human dimension into environmental decision-making. Decision-makers need knowledge of the human dimension of resource systems and of the social consequences of decision-making if environmental management is to be effective and adaptive. Social scientists have a central role to play, but little guidance exists to help them influence decision-making processes. We distil 348 years of cumulative experience shared by 31 environmental experts across three continents into advice for social scientists seeking to increase their influence in the environmental policy arena. Results focus on the importance of process, engagement, empathy and acumen and reveal the importance of understanding and actively participating in policy processes through co-producing knowledge and building trust. The insights gained during this research might empower a science-driven cultural change in science-policy relations for the routine integration of the human dimension in environmental decision making; ultimately for an improved outlook for earth’s ecosystems and the billions of people that depend on them.
We studied the effect of ocean acidification (OA) on a coastal North Sea plankton community in a long-term mesocosm CO2-enrichment experiment (BIOACID II long-term mesocosm study). From March to July 2013, 10 mesocosms of 19 m length with a volume of 47.5 to 55.9 m3 were deployed in the Gullmar Fjord, Sweden. CO2 concentrations were enriched in five mesocosms to reach average CO2 partial pressures (pCO2) of 760 μatm. The remaining five mesocosms were used as control at ambient pCO2 of 380 μatm. Our paper is part of a PLOS collection on this long-term mesocosm experiment. Here, we here tested the effect of OA on total primary production (PPT) by performing 14C-based bottle incubations for 24 h. Furthermore, photoacclimation was assessed by conducting 14C-based photosynthesis-irradiance response (P/I) curves. Changes in chlorophyll a concentrations over time were reflected in the development of PPT, and showed higher phytoplankton biomass build-up under OA. We observed two subsequent phytoplankton blooms in all mesocosms, with peaks in PPT around day 33 and day 56. OA had no significant effect on PPT, except for a marginal increase during the second phytoplankton bloom when inorganic nutrients were already depleted. Maximum light use efficiencies and light saturation indices calculated from the P/I curves changed simultaneously in all mesocosms, and suggest that OA did not alter phytoplankton photoacclimation. Despite large variability in time-integrated productivity estimates among replicates, our overall results indicate that coastal phytoplankton communities can be affected by OA at certain times of the seasonal succession with potential consequences for ecosystem functioning.