Good governance is paramount to the sustainability of fisheries, and inclusiveness of stakeholder groups has become the centerpiece in the ethos of managing small-scale fisheries. Understanding the effect of governance network structures on fishery sustainability can help guide governance to achieve desired outcomes. Data on resource users, fishing methods, governance networks and classifications of stock health were compiled for 17 sea cucumber fisheries in the Indian Ocean. The subjective influence of the actors and the complexity of governance networks on the health of wild stocks were analyzed. The fisheries differed widely in their resource users, fishing methods and governance networks. Little correspondence was found between the number of nodes in the governance networks and the health (exploitation status) of wild stocks. Government entities dominated the networks but neither their relative influence in the networks nor their proportionate contribution to the number of entities in the networks greatly affected stock health. These findings do not refute the benefits of inclusive governance, but rather suggest that multiple other factors (e.g. inadequate regulations, weak enforcement, high number of fishers) are also likely to play a role in influencing sea cucumber fishery sustainability. These factors must be tackled in tandem with good governance.
Previous studies have helped define what good ocean planning (also known as maritime or marine spatial planning) looks like, effective stakeholder engagement, possible conservation and community benefits, and how ocean plans could theoretically cut costs and create economic value. But little evidence has yet been compiled showing the actual results of ocean plans, and whether or not they have delivered on their promise to balance competing interests through a collaborative process that considers environmental concerns. This paper presents an empirical study of five government-approved ocean plans, all of which resulted in broadly shared net benefits. Economically, these five ocean plans delivered on average $60 million per year in value from new industries and retained value in existing industries, although some stakeholders bore losses and government spending did not decrease. Environmentally, planning increased marine protection, ensured industrial uses avoided sensitive habitat, cut carbon emissions, and reduced the risk of oil spills. Socially, marine planning increased broad stakeholder engagement (thus improving design and administration of plans), while building trust that will likely improve sustainable future use of ocean space.
There is an open question among conservation practitioners regarding whether using flagship specifies to market marine conservation is less effective than using terrestrial species in the terrestrial context. A flagship species is a species selected to act as an ambassador, icon, or symbol for a defined habitat, issue, campaign, or environmental cause. A mascot species has many of the same attributes as a flagship species, but is selected for its communications value instead of its ecological value. Our research indicates that mascot species can be as effective a marketing tool for marine conservation as they have been for terrestrial conservation. Based on our study, there is no evidence that the use of marine mascot species or that confront threats based on fishing and harvesting of aquatic resources perform any differently from other social marketing campaigns that address terrestrial issues.
Conventionally flood mapping typically includes only a static water level (e.g. peak of a storm tide) in coastal flood inundation events. Additional factors become increasingly important when increased water-level thresholds are met during the combination of a storm tide and increased mean sea level. This research incorporates factors such as wave overtopping and river flow in a range of flood inundation scenarios of future sea-level projections for a UK case study of Fleetwood, northwest England. With increasing mean sea level it is shown that wave overtopping and river forcing have an important bearing on the cost of coastal flood events. The method presented converts inundation maps into monetary cost. This research demonstrates that under scenarios of joint extreme surge-wave-river events the cost of flooding can be increased by up to a factor of 8 compared with an increase in extent of up to a factor of 3 relative to “surge alone” event. This is due to different areas being exposed to different flood hazards and areas with common hazard where flood waters combine non-linearly. This shows that relying simply on flood extent and volume can under-predict the actual economic impact felt by a coastal community. Additionally, the scenario inundation depths have been presented as “brick course” maps, which represent a new way of interpreting flood maps. This is primarily aimed at stakeholders to increase levels of engagement within the coastal community.
Alternative stable states in ecology have been well studied in isolated, well-mixed systems. However, in reality, most ecosystems exist on spatially extended landscapes. Applying existing theory from dynamic systems, we explore how such a spatial setting should be expected to affect ecological resilience. We focus on the effect of local disturbances, defining resilience as the size of the area of a strong local disturbance needed to trigger a shift. We show that in contrast to well-mixed systems, resilience in a homogeneous spatial setting does not decrease gradually as a bifurcation point is approached. Instead, as an environmental driver changes, the present dominant state remains virtually ‘indestructible’, until at a critical point (the Maxwell point) its resilience drops sharply in the sense that even a very local disturbance can cause a domino effect leading eventually to a landscape-wide shift to the alternative state. Close to this Maxwell point the travelling wave moves very slow. Under these conditions both states have a comparable resilience, allowing long transient co-occurrence of alternative states side-by-side, and also permanent co-existence if there are mild spatial barriers. Overall however, hysteresis may mostly disappear in a spatial context as one of both alternative states will always tend to be dominant. Our results imply that local restoration efforts on a homogeneous landscape will typically either fail or trigger a landscape-wide transition. For extensive biomes with alternative stable states, such as tundra, steppe and forest, our results imply that, as climatic change reduces the stability, the effect might be difficult to detect until a point where local disturbances inevitably induce a spatial cascade to the alternative state.
Scientifically-based systematic conservation planning for reserve design requires knowledge of species richness patterns and how these are related to environmental gradients. In this study, we explore a large inventory of coastal breeding birds, in total 48 species, sampled in 4646 1 km2 squares which covered a large archipelago in the Baltic Sea on the east coast of Sweden. We analysed how species richness (α diversity) and community composition (β diversity) of two groups of coastal breeding birds (specialists, i.e. obligate coastal breeders; generalists, i.e. facultative coastal breeders) were affected by distance to open sea, land area, shoreline length and archipelago width. The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists. The number of specialist bird species per square increased with decreasing distance to open sea, while the opposite was true for the generalists. Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately. Fourteen species were nationally red-listed, and showed similar relationships to the environmental gradients as did all species, specialists and generalists. We suggest that availability of suitable breeding habitats, and probably also proximity to feeding areas, explain much of the observed spatial distributions of coastal birds in this study. Our findings have important implications for systematic conservation planning of coastal breeding birds. In particular, we provide information on where coastal breeding birds occur and which environments they seem to prefer. Small land areas with long shorelines are highly valuable both in general and for red-listed species. Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection.
Overexploitation is a major threat for the integrity of marine ecosystems. Understanding the ecological consequences of different extractive practices and the mechanisms underlying the recovery of populations is essential to ensure sustainable management plans. Precious corals are long-lived structural invertebrates, historically overfished, and their conservation is currently a worldwide concern. However, the processes underlying their recovery are poorly known. Here, we examined harvesting effects and recovery mechanisms of red coral Corallium rubrum by analyzing long-term photographic series taken on two populations that were harvested. We compared the relative importance of reproduction and re-growth as drivers of resilience. Harvesting heavily impacted coral populations causing large decreases in biomass and strong size-class distribution shifts towards populations dominated by small colonies. At the end of the study (after 4 and 7 years) only partial recovery was observed. The observed general pattern of low recruitment and high mortality of new recruits demonstrated limited effects of reproduction on population recovery. Adversely, low mortality of partially harvested adults and a large proportion of colonies showing new branches highlighted the importance of re-growth in the recovery process. The demographic projections obtained through stochastic models confirmed that the recovery rates of C. rubrum can be strongly modulated depending on harvesting procedures. Thus, leaving the basal section of the colonies when harvesting to avoid total mortality largely enhances the resilience of C. rubrum populations and quickens their recovery. On the other hand, the high survival of harvested colonies and the significant biomass reduction indicated that abundance may not be an adequate metric to assess the conservation status of clonal organisms because it can underestimate harvesting effects. This study highlights the unsustainability of current harvesting practices of C. rubrum and provides urgently needed data to improve management practices that are still largely based on untested assumptions.
The susceptibility of reef-building corals to climatic anomalies is well documented and a cause of great concern for the future of coral reefs. Reef corals are normally considered to tolerate only a narrow range of climatic conditions with only a small number of species considered heat-tolerant. Occasionally however, corals can be seen thriving in unusually harsh reef settings and these are cause for some optimism about the future of coral reefs. Here we document for the first time a diverse assemblage of 225 species of hard corals occurring in the intertidal zone of the Bonaparte Archipelago, north western Australia. We compare the environmental conditions at our study site (tidal regime, SST and level of turbidity) with those experienced at four other more typical tropical reef locations with similar levels of diversity. Physical extremes in the Bonaparte Archipelago include tidal oscillations of up to 8 m, long subaerial exposure times (>3.5 hrs), prolonged exposure to high SST and fluctuating turbidity levels. We conclude the timing of low tide in the coolest parts of the day ameliorates the severity of subaerial exposure, and the combination of strong currents and a naturally high sediment regime helps to offset light and heat stress. The low level of anthropogenic impact and proximity to the Indo-west Pacific centre of diversity are likely to further promote resistance and resilience in this community. This assemblage provides an indication of what corals may have existed in other nearshore locations in the past prior to widespread coastal development, eutrophication, coral predator and disease outbreaks and coral bleaching events. Our results call for a re-evaluation of what conditions are optimal for coral survival, and the Bonaparte intertidal community presents an ideal model system for exploring how species resilience is conferred in the absence of confounding factors such as pollution.
Concern for the future of reef-building corals in conditions of rising sea temperatures combined with recent technological advances has led to a renewed interest in documenting the biodiversity of mesophotic coral ecosystems (MCEs) and their potential to provide lineage continuation for coral taxa. Here, we examine species diversity of staghorn corals (genera Acropora and Isopora) in the mesophotic zone (below 30 m depth) of the Great Barrier Reef and western Coral Sea. Using specimen-based records we found 38 staghorn species in the mesophotic zone, including three species newly recorded for Australia and five species that only occurred below 30 m. Staghorn corals became scarce at depths below 50 m but were found growing in-situ to 73 m depth. Of the 76 staghorn coral species recorded for shallow waters (depth ≤ 30 m) in north-east Australia, 21% extended to mesophotic depths with a further 22% recorded only rarely to 40 m depth. Extending into the mesophotic zone provided shallow water species no significant advantage in terms of their estimated global range-size relative to species restricted to shallow waters (means 86.2 X 106 km2 and 85.7 X 106 km2 respectively, p = 0.98). We found four staghorn coral species at mesophotic depths on the Great Barrier Reef that were previously considered rare and endangered on the basis of their limited distribution in central Indonesia and the far western Pacific. Colonies below 40 m depth showed laterally flattened branches, light and fragile skeletal structure and increased spacing between branches and corallites. The morphological changes are discussed in relation to decreased light, water movement and down-welling coarse sediments. Staghorn corals have long been regarded as typical shallow-water genera, but here we demonstrate the significant contribution of this group to the region’s mesophotic fauna and the importance of considering MCEs in reef biodiversity estimates and management.
Understanding the influence of synergisms on natural processes is a critical step toward determining the full-extent of anthropogenic stressors. As carbon emissions continue unabated, two major stressors—warming and acidification—threaten marine systems on several scales. Here, we report that a moderate temperature increase (from 30°C to 32°C) is sufficient to slow— even hinder—the ability of dissolved organic matter, a major carbon pool, to self-assemble to form marine microgels, which contribute to the particulate organic matter pool. Moreover, acidification lowers the temperature threshold at which we observe our results. These findings carry implications for the marine carbon cycle, as self-assembled marine microgels generate an estimated global seawater budget of ~1016 g C. We used laser scattering spectroscopy to test the influence of temperature and pH on spontaneous marine gel assembly. The results of independent experiments revealed that at a particular point, both pH and temperature block microgel formation (32°C, pH 8.2), and disperse existing gels (35°C). We then tested the hypothesis that temperature and pH have a synergistic influence on marine gel dispersion. We found that the dispersion temperature decreases concurrently with pH: from 32°C at pH 8.2, to 28°C at pH 7.5. If our laboratory observations can be extrapolated to complex marine environments, our results suggest that a warming–acidification synergism can decrease carbon and nutrient fluxes, disturbing marine trophic and trace element cycles, at rates faster than projected.