- Indicators of ecosystem status are of increasing importance for management. Many studies infer associations between the environment and fish communities, but little is known about how fish community indicators are related to temporal variation in anthropogenic and hydroclimate drivers, and on what geographical scale, these indicators are representative.
- Here, we investigate the spatial synchrony of seven indicators of coastal fish community status among eleven reference sites 2002–2014 in the Baltic Sea. At three of these sites, we study the temporal covariation between indicators and anthropogenic and hydroclimate drivers over 25 years.
- The indicators (abundance of) – Perch, Large Piscivores and Non-perch Piscivores – showed spatial synchrony over the study scale (100–1000 km), whereas temporal dynamics of other indicators reflected changes at scales <100 km.
- At the studied reference sites, temporal changes of indicators were mainly associated with climate-related hydrological variables, but nutrient-related variables were important in the northern Baltic Sea. Landings showed no associations with any indicator. Four of the indicators showed evident temporal autocorrelation reflecting an influence of internal population/community processes.
- Synthesis and applications. Environmental status of coastal fish communities in the Baltic Sea should be assessed and managed at a local scale. The main drivers of fish community indicators of ecosystem status tend to differ between coastal areas, but among the reference sites assessed in this study, hydroclimatic variation and internal processes seem to be of greater importance for the temporal development of indicators than anthropogenic pressures. Therefore, when assessing the status of coastal fish communities and evaluating management measures in areas impacted by anthropogenic activities, it is important to account for variation in salinity, temperature and time lags.
South Africa recently had the privilege of hosting prominent fisheries scientist Professor Ray Hilborn from Washington University who stimulated lively discussion on global stock status, food production, impacts of trawling on the seabed, fisheries management and Marine Protected Areas (MPAs). Professor Hilborn gave a seminar billed as 'Fisheries Myths' on 25 August 2016 and the following day participated in a formal debate at the Two Oceans Aquarium on South Africa's MPA expansion strategy and the need for additional MPAs. The debate was held between Professors Ray Hilborn and Doug Butterworth (Marine Resource and Assessment Management Group, Applied Mathematics Department, University of Cape Town) speaking against the strategy and expansion, and Dr Jean Harris (Ezemvelo KwaZulu-Natal Wildlife and Pew Fellow) and Professor Colin Attwood (Department of Biological Sciences, University of Cape Town) speaking in favour of additional MPAs. The debate examined the need for MPA expansion; the effect of MPAs on fisheries; and the role of MPAs in fisheries management, food security and biodiversity protection; and interrogated targets to increase ocean protection.
Here I examine key aspects of these discussions in the context of the proposed new Phakisa MPA Network developed through Operation Phakisa Oceans Economy - the presidential initiative to explore and unlock the economic potential of South Africa's marine and coastal environment. This network of 22 proposed MPAs was published for public comment in February this year.
Expected increases in pluvial flooding, due to climatic changes, require large investments in the retrofitting of cities to keep damage at an acceptable level. Many cities have investigated the possibility of implementing stormwater management (SWM) systems which are multi-functional and consist of different elements interacting to achieve desired safety levels. Typically, an economic assessment is carried out in the planning phase, while environmental sustainability is given little or no attention. In this paper, life cycle assessment is used to quantify environmental impacts of climate change adaptation strategies. The approach is tested using a climate change adaptation strategy for a catchment in Copenhagen, Denmark. A stormwater management system, using green infrastructure and local retention measures in combination with planned routing of stormwater on the surfaces to manage runoff, is compared to a traditional, sub-surface approach. Flood safety levels based on the Three Points Approach are defined as the functional unit to ensure comparability between systems. The adaptation plan has significantly lower impacts (3–18 person equivalents/year) than the traditional alternative (14–103 person equivalents/year) in all analysed impact categories. The main impacts are caused by managing rain events with return periods between 0.2 and 10 years. The impacts of handling smaller events with a return period of up to 0.2 years and extreme events with a return period of up to 100 years are lower in both alternatives. The uncertainty analysis shows the advantages of conducting an environmental assessment in the early stages of the planning process, when the design can still be optimised, but it also highlights the importance of detailed and site-specific data.
The three main pillars of the European Common Fisheries Policy, reformed in 2013, consist of minimizing ecological impacts; implementing sustainable exploitation defined by maximum sustainable yield (MSY) for regulated species and introducing landing obligations aimed at reducing the wasteful practice of discarding unwanted catches. These three key elements constitute major challenges for fisheries, their management and fishery scientists whose goal is to provide objective advice. We demonstrate that limiting sustainable catch options may pose rigorous constraints on fishing activities, in particular on so-called mixed fisheries targeting more than one individual stock. In a situation where there are complex restrictions comprising multiple management goals which are sometimes conflicting (e.g. the ‘choke effects’ of reduced catch opportunities due to specific stock conservation needs or market conditions), we propose the application of specific measures for specific fisheries, i.e. deviation from traditional fishery selection patterns, as an option to avert significant losses in yield and economic revenue. Fisheries-specific contributions to general management goals, including unwanted effects, shall be evaluated. Individual fisheries may benefit accordingly through multi-annual management plans with regional-scale reconciliation of sustainable exploitation of living natural resources, food security and socio-economy as potential key elements.
Improving our knowledge of cetacean distribution and habitat use are key if we are to effectively ensure good conservation status for these species. Often however, sufficient data are lacking, inhibiting conservation efforts of many species. This study aims to combine historical datasets to generate habitat suitability models and thus maps, for eight species of cetacean regularly sighted in the Irish portion of the northeast Atlantic; fin whale, minke whale, pilot whale, sperm whale, white-sided dolphin, bottlenose dolphin, Risso's dolphin and white-beaked dolphin. Habitat suitability models were developed using MaxEnt modelling software for a range of environmental factors; sea-surface temperature, mixed layer depth, depth, slope, chlorophyll a concentration, sea surface salinity, distance to the 200 m contour. We predicted species exposure to fishing gears by integrating habitat suitability models with information on fishing vessel activities within the study area. The main predictors of habitat suitability for all species were topographic variables, particularly depth and slope, highlighted by two areas of high species richness around areas of topographic heterogeneity, along the continental shelf and on the west coast. Combining habitat models with fishing activity, indicated areas of high exposure off the north and south coasts and in an area known as the Porcupine Bank off the west coast. These results are valuable for conservation and management of cetaceans and fisheries in the study area. Methods can be easily adjusted to allow replication for other species and other anthropogenic activities. We recommend future effort focuses on winter months to fill in the gaps on year round cetacean distribution.
There is an increasing recognition that marine and coastal ecosystems are under severe threat. The implementation of Marine Protected Areas (MPAs) has become a cornerstone in addressing these impacts. The formulation of the Aichi Target (AT) 11 has acknowledged the benefits of MPAs as a vital approach to achieve marine conservation targets. In the AT 11, reference to the term “equitably managed” has demonstrated the importance of equity in the planning and management of MPAs and in this paper, a description of how equity should be considered from the inception stage is detailed. Two case studies, one in Japan and the other in the Solomon Islands, were chosen because they include equity considerations from the inception and were successful in reaching their conservation targets. Through these two case studies, it is demonstrated that understanding the objectives and expectations of all stakeholders can help achieve the qualitative goals of the AT 11. This is particularly true for local and indigenous communities in Small Island Developing States (SIDS) and coastal communities in developing countries. Finally, a set of recommendations has been provided to address possible limitations that could arise during the MPA design exercise. Participatory area management and spatial and temporal zoning can help by ensuring that benefits and costs are distributed equitably between stakeholders.
The participation of local communities in marine resource management can contribute to the sustainability and longevity of marine resources across diverse coastal settings. In contexts where there are low levels of formal education and high levels of illiteracy, and where marine resource management is governed predominantly by customary management systems, the introduction of formal marine resource management can be challenging. Maps are often required as the basis for spatial marine management measures, effective spatially-explicit fisheries monitoring, and for formal support from fisheries authorities. Our research with local women reef gleaners of Cabo Delgado, in northern Mozambique, pilots the potential uses of smartphones and digital mapping as a tool to allow fishers to map these understudied intertidal fishing grounds, and to understand the ecological dynamics as well as social uses of the intertidal resources. Even though women are key food and income providers through intertidal resource gleaning in this area of Mozambique, they have limited roles in fisheries management decision making. Therefore, we developed a participatory approach to mapping that could act as an entry point for their involvement in the design of a spatial fisheries management plan and associated community monitoring. Fisherwomen were trained to use smartphones with CyberTracker software for mapping intertidal fishing grounds in their village, and the locations of intertidal resources most important to their livelihoods, including octopus, pen shells and oysters. Interviews and focus groups were conducted throughout the mapping process to ascertain women's use and interest in the technology. We conclude that community-based mapping through simple tools as developed in this research can help connect local community groups, bridge traditional and formal governance systems and provide a positive example of co-management in practice.
In this study, a long-term assessment of the wave energy resource potential for the Australian southeast shelf is performed from deep to shallow water, based on a 31-year wave hindcast. The hindcast, covering the period from 1979 to 2010, has been performed at high spatio-temporal resolution with the wave energy transformation model SWAN using calibrated source-term parameters. The model has been applied with a variable spatial resolution of up to approximately 500 m and at 1 h temporal resolution and driven with high-resolution, non-stationary CFSR wind fields and full 2D spectral boundary conditions from WaveWatch III model. Model validation was conducted against wave measurements from multiple buoy sites covering 10–31 years and showed a relatively high correlation between hindcast and measured significant wave height (Hs) and mean wave direction (θm).
Maps of wave power resource distribution for annual and seasonal mean potential were generated along with the maps of resource reliability and variability. The high resolution allowed us to perform in-depth analysis of wave power characteristics, providing resource knowledge on seasonal and longer-term variability necessary for reliable and optimal design of wave technology. The most promising area for wave power exploitation was found to be the central coast of New South Wales, where various high-energy hotspots were selected for a further analysis. For each of the considered hotspots, the wave power magnitude, variability and consistency were carefully assessed and characterized by means of sea state parameters and mean wave directions. Finally, estimates of electric power outputs from different types of pre-commercial wave energy converter devices were drawn for each hotspot based on the wave data hindcast and discussed.
Oil pollution in the Mediterranean represents a serious threat to the coastal environment. Quantifying the risks associated with a potential spill is often based on results generated from oil spill models. In this study, MEDSLIK-II, an EU funded and endorsed oil spill model, is used to assess potential oil spill scenarios at four pilot areas located along the northern, eastern, and southern Mediterranean shoreline, providing a wide range of spill conditions and coastal geomorphological characteristics. Oil spill risk assessment at the four pilot areas was quantified as a function of three oil pollution metrics that include the susceptibility of oiling per beach segment, the average volume of oiling expected in the event of beaching, and the average oil beaching time. The results show that while the three pollution metrics tend to agree in their hazard characterization when the shoreline morphology is simple, considerable differences in the quantification of the associated hazard is possible under complex coastal morphologies. These differences proved to greatly alter the evaluation of environmental risks. An integrative hazard index is proposed that encompasses the three simulated pollution metrics. The index promises to shed light on oil spill hazards that can be universally applied across the Mediterranean basin by integrating it with the unified oil spill risk assessment tool developed by the Regional Marine Pollution Emergency Response Centre for the Mediterranean (REMPEC).
- Retrospective determination of location for marine animals would facilitate investigations of migration, connectivity and food provenance. Predictable spatial variations in carbon and nitrogen isotopes in primary production across shelf seas provide a basis for stable isotope-based location.
- Here, we assess the accuracy and precision that can be obtained through dietary-isotope-based location methods. We build isoscapes from jellyfish tissues and use these to assign scallops of fixed and known individual location, and herring with well-understood population-level distributions in the North Sea.
- Accuracy and precision for retrospective isotope-based location in the North Sea were of a similar order to light-based location devices, with 75% of individual scallops assigned correctly to areas representing c. 30% of the North Sea, with a mean linear error on the order of 102 km. Applying assignment methods to an alternative migratory species (herring) resulted in ecologically realistic assignments consistent with fisheries survey data.
- Location methods based on dietary isotopes such as carbon and nitrogen recover the spatial origin of nutrients assimilated into tissues, and this may not correspond directly to the physical location if either the test animal or its prey is highly migratory. Stable isotope-based location can be applied to any marine-feeding organism or derived food product, but the ecological meaning of any assigned area will be more difficult to interpret for large, high trophic level, migratory animals with relatively slow isotopic assimilation rates.