The species composition of fish communities in 15 microtidal estuaries in south-western Australia, ranging from permanently-open to normally-closed, is shown to be related to the geomorphological and hydrological regimes and not to environmental condition. This study then explored the effectiveness of using qualitative taxonomic distinctness and ABC curves for fish data as indicators of the environmental condition in nearshore, shallow waters of these estuaries and, in the case of taxonomic distinctness, also of their offshore, deeper waters. Neither of these indices require spatial or temporal reference data, which may be either prohibitively expensive and time-consuming to collect or unavailable. Taxonomic distinctness, in both nearshore and offshore waters, varied consistently among estuaries in relation to their recorded environmental status, and is thus a good indicator of overall estuarine condition. ABC analyses, however, did not prove a good measure of the environmental condition of the estuaries, because their results largely reflect differences in accessibility of the estuary to marine estuarine-opportunist species and especially those that grow to a larger size. It is concluded that taxonomic distinctness indices provide a rapid and cost-effective method for assessing the environmental condition of estuaries, particularly those with limited spatial or temporal reference data.
Many coastal habitats are actually replaced with hard infrastructures which alter the taxonomic/functional structure of natural ecosystems worldwide. Few information about habitat loss and species composition in South American coasts are available compared with other coasts. Here, I examine the distribution and identity of coastal artificial infrastructures, especially artificial breakwaters, present along the coast of Chile and the proportion of natural habitat loss derived from their construction. Differences in species taxonomic/functional composition in artificial breakwaters and natural habitats present in northern Chile are also examined. I also propose/discuss opportunities for coastal planning based on habitat rehabilitation and ecological engineering in Chile, which could guide future marine infrastructures construction. An important proportion of natural habitat has been replaced by artificial coastal defences along the coast of Chile, accounting for about 200 km of total coastal length. Given their specific uses and functions, artificial granite breakwaters are one of the most important coastal infrastructures present in Chile (62% of the total of artificial breakwaters present). Differences in taxonomic/functional structure between artificial breakwaters and natural adjacent habitats are significant, and appear related to contrasting spatial heterogeneity. Artificial infrastructures like granite breakwaters can facilitate presence of native and non-native species, which live in the marine-terrestrial interphase (crabs, rats). The present study highlights how the recent proliferation of coastal artificial infrastructures is replacing important natural habitats in Chile, and how the taxonomic/functional structure of coastal ecosystems can be negatively impacted. Furthermore, this study showed how artificial infrastructures can have direct consequences for human-health security and specific guidelines can be conducted to buffer impacts on ecosystem structure to match social livelihood and wellness.
Sustainable development is the framing concept assuring that resources are exploited while maintaining the ability of these natural resources to provide for future generations. With human dependence on marine resources increasing, Ecosystem-Based Management (EBM) has been identified as a suitable approach to ensure sustainable development. In order to achieve this, the core principles and elements of EBM should be operational in the maritime/marine spatial planning (MSP) process to ensure that human activities in marine space are ordered to attain ecological, economic and social objectives. However, policies from various states and organizations sometimes do not set a clear precedence for translating principles of EBM and present different and complex approaches to an ecosystem-based marine spatial planning (EB-MSP). Again, a feasible methodology for EBM to be operational in MSP is still vague. This paper therefore presents results from a survey and review of MSP initiatives in Europe, Asia and the Americas. Results showed that essential MSP steps and elements such as adaptive management, setting of planning boundaries, understanding and analysing the ecosystem and future conditions are not fully operational. This paper focuses on a methodology for EB-MSP and gives recommendations on how to ensure that EBM is operational at each stage of an MSP process. It stresses the importance of setting planning boundaries beyond jurisdictional borders to consider bio/eco-regions and cover near-shore waters, the need to have a cross-sector integration, understanding the ecosystem through having an ecosystem service perspective and having a legal framework to ensure that results from monitoring and evaluating of plans are adapted through review and revision.
Effective coastal management is integrative and aims to incorporate the wide variety of user needs, values and interests associated with coastal environments. This requires understanding how different user groups relate to coastal environments as ‘places’, imbued with values and meanings, rather than simply ‘spaces’. Accordingly, tools and techniques that can capture and convey place-based information have potential for supporting coastal management strategies. This suggests a role for geovisualizations that inclusively reflect the range of values and meanings through immersion and realism. The current paper aims to advance coastal geovisualization research by firstly, examining relationships with, understandings of, and behaviours toward coastal places, and secondly, using this insight to create recommendations for building geovisualizations that can effectively facilitate collaboration among conflicting user groups. The paper identifies different coastal user groups using a cultural model framework, and through a review of previous research on coastal communities, it examines how the values and interests of these user groups influence understandings and perceptions of coastal places. Recommendations for geovisualizations emerging from this research include full navigability, dynamic elements, and flexibility in the way that they allow for continual modification and scenario building.
1.Climate change is impacting different species at different rates, leading to alterations in biological interactions with ramifications for wider ecosystem functioning. Understanding these alterations can help improve predictive capacity and inform management efforts designed to mitigate against negative impacts. 2.We investigated how the movement and space use patterns of polar bears (Ursus maritimus) in coastal areas in Svalbard, Norway, have been altered by a sudden decline in sea ice that occurred in 2006. We also investigated whether the spatial overlap between polar bears and their traditionally most important prey, ringed seals (Pusa hispida), has been affected by the sea-ice decline, as polar bears are dependent on a sea-ice platform for hunting seals. 3.We attached biotelemetry devices to ringed seals (n=60, both sexes) and polar bears (n=67, all females) before (2002-2004) and after (2010-2013) a sudden decline in sea ice in Svalbard. We used linear mixed-effects models to evaluate the association of these species to environmental features and an approach based on Time Spent in Area to investigate changes in spatial overlap between the two species. 4.Following the sea-ice reduction, polar bears spent the same amount of time close to tidal glacier fronts in the spring but less time in these areas during the summer and autumn. However, ringed seals did not alter their association with glacier fronts during summer, leading to a major decrease in spatial overlap values between these species in Svalbard's coastal areas. Polar bears now move greater distances daily and spend more time close to ground-nesting bird colonies, where bear predation can have substantial local effects. 5.Our results indicate that sea-ice declines have impacted the degree of spatial overlap and hence the strength of the predator-prey relationship between polar bears and ringed seals, with consequences for the wider Arctic marine and terrestrial ecosystems. Shifts in ecological interactions are likely to become more widespread in many ecosystems as both predators and prey respond to changing environmental conditions induced by global warming, highlighting the importance of multi-species studies.
Shellfish farming is an expanding segment of marine aquaculture, but the impact of this industry on coastal cetacean species is only beginning to be considered. The interaction between mussel farming and coastal cetaceans in one of the world’s leading producers of this bivalve (Galicia, NW Spain) was studied. Specifically, the habitat use of common bottlenose dolphins (Tursiops truncatus) was evaluated in relation to environmental, geographical, and anthropogenic variables. Over a period of 22 months spent in the field, 154 daily boat surveys and 353 common bottlenose dolphin encounters were done. Results of this study confirm that areas of mussel production are frequently utilized by common bottlenose dolphins. Of the investigated factors, shellfish farms appeared to have a clear effect, with increased bottlenose dolphin occurrence at mussel farm locations and in waters close to the aquaculture zones. These observations contrast with previous studies where the occurrence and distribution of coastal cetacean species decreased in association with shellfish aquaculture representing a source of habitat loss and causing potentially negative effects. These differences suggest that the interactions between shellfish aquaculture and cetaceans are affected by the culture method and cetacean species involved. The positive relationships between dolphins’ occurrence and mussel aquaculture zones are presumably the result of large aggregations of fish species around mussel rafts, which provide high densities of high-quality prey for dolphins. This study provides new insights into the understanding of how shellfish aquaculture influences coastal dolphins and hence support the design of policies aimed at implementing ecosystem management principles.
We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length-weight relationships, as well as the economy of scientific sampling (using the entire catch to acquire data on as many biological characteristics as possible) are discussed.
Targets and limits for long-term management are used in fisheries advice to operationalize the way management reflects societal priorities on ecological, economic, social and institutional aspects. This study reflects on the available published literature as well as new research presented at the international ICES/Myfish symposium on targets and limits for long term fisheries management. We examine the inclusion of ecological, economic, social and institutional objectives in fisheries management, with the aim of progressing towards including all four objectives when setting management targets or limits, or both, for multispecies fisheries. The topics covered include ecological, economic, social and governance objectives in fisheries management, consistent approaches to management, uncertainty and variability, and fisheries governance. We end by identifying ten ways to more effectively include multiple objectives in setting targets and limits in ecosystem based fisheries management.
The contribution by women to fisheries economies globally continues to be overlooked, in part, because “fishing” is often narrowly defined as catching fish at sea, from a vessel, using specialized gears. Both men and women are involved in fisheries, but often in different roles and activities. Fisheries research, management, and policy have traditionally focused on direct, formal, and paid fishing activities—that are often dominated by men, ignoring those that are indirect, informal, and/or unpaid—where women are concentrated. This has led to a situation where men's and women's contributions to fisheries are not equally valued or even recognized and has resulted in women being largely excluded from fisheries decision-making processes. Here, we examine the contributions by women in the fisheries sector of five globally significant marine fishing countries—Mexico, Peru, Senegal, South Africa, and Vietnam. These countries each have strong links between livelihoods and marine capture fisheries, yet represent different geographic, socioeconomic, and governance contexts. Through a synthesis of existing data, case studies, and consultation with local experts, we found that the contribution by women to the fisheries of these five countries is substantial. However, this investigation also revealed major gaps in understanding of gender inequalities in the fisheries sector and the need for better gender-disaggregated data to inform fisheries policy.
The ‘Wild Seafood’ Provisioning Service (WSPS), on which commercial fisheries rely, is probably one of the best studied marine ecosystem services due to its economic relevance and because extensive information sources exist for assessment purposes. Yet, the indicators often proposed are not suitable to describe the capacity of the ecosystem to deliver the WSPS. Therefore this study proposes surplus production (SP), a well-established concept in fisheries science, as the basis to calculate the capacity of marine ecosystems to provide the WSPS. SP is defined as the difference between stock production (through recruitment and body growth) and losses through natural mortality. This is, therefore, the production of the stock that could be harvested sustainably without decreasing the biomass. To assess the sustainability of the exploitation of the WSPS we also developed an indicator for this based on SP and compared it to existing fisheries management indicators. When both SP-based indicators showed a decreasing trend, contrasting with an increasing trend in the existing fisheries management indicators, the calculation of the SP-based indicators was scrutinized revealing that the weighting of the stocks into an aggregated indicator, strongly determines the indicator values, even up to the point that the trend is reversed. The aggregated indicators based on SP-weighted stocks can be considered complementary to existing fisheries management indicators as the former accurately reflect the capacity of the commercial fish to provide the WSPS and the sustainability of the exploitation of this service. In contrast the existing fisheries management indicators primarily reflect the performance of management towards achieving fisheries-specific policy goals.