Distance from a fishing community explains fish abundance in a no-take zone with weak compliance

A diverse portfolio of marine protected areas can better advance global conservation and equity

Marine protected areas (MPAs) are widely used for ocean conservation, yet the relative impacts of various types of MPAs are poorly understood. We estimated impacts on fish biomass from no-take and multiple-use (fished) MPAs, employing a rigorous matched counterfactual design with a global dataset of >14,000 surveys in and around 216 MPAs. Both no-take and multiple-use MPAs generated positive conservation outcomes relative to no protection (58.2% and 12.6% fish biomass increases, respectively), with smaller estimated differences between the two MPA types when controlling for additional confounding factors (8.3% increase). Relative performance depended on context and management: no-take MPAs performed better in areas of high human pressure but similar to multiple-use in remote locations. Multiple-use MPA performance was low in high-pressure areas but improved significantly with better management, producing similar outcomes to no-take MPAs when adequately staffed and appropriate use regulations were applied. For priority conservation areas where no-take restrictions are not possible or ethical, our findings show that a portfolio of well-designed and well-managed multiple-use MPAs represents a viable and potentially equitable pathway to advance local and global conservation.

Checklist of coral reef fishes of Darvel Bay, Sabah, Malaysian Coral Triangle, with a note on the biodiversity and community structure

The Darvel Bay is a large semi-enclosed bay with spectacular natural land and seascape. The inward side of the Bay has only been recently known to be an important foraging ground for the endangered, threatened and protected (ETP) elasmobranch species, such as the Whale Shark and mobulid rays. Following a recent scientific expedition, we present a checklist of the coral reef fishes of Darvel Bay. A note on the biodiversity and community structure is presented, based on our analysis using diversity indices, univariate and multivariate approaches. Seven natural coral reefs comprising two fringing reefs and five patch reefs, were surveyed at 10 m depth using underwater visual census (UVC) and baited remote underwater video station (BRUVS) methods. A diverse list of 66 species of reef fishes from 17 families is recorded. However, this is overwhelmingly dominated by the small-sized omnivorous damselfish, family Pomacentridae (62%; N = 1485 individuals). Species richness and abundance were observed to increase at sites surveyed furthest from the coast within the Bay. Significantly distinct reef fish assemblages were observed between three priori groups, based on proximity to shore (ANOSIM, R = 0.65, p < 0.05). SIMPER analysis further revealed that 22 species of the total reef fish species recorded drive 76% dissimilarities between the groups. The pattern of the reef fish communities observed, reflected as a logseries distribution model, is that commonly found in disturbed habitats or habitats characterised by restricted resources in a community, where the dominant species takes up a high proportion of available resources. The ecological indices (Shannon-Wiener Diversity Index, 2.05; Simpson Index of Diversity, 0.79; Simpson Dominance Index, 0.20; and Pielou's Evenness Index, 0.43), all reflect the relatively low diversity and uneven species distribution of the reef fish community. We conclude that the present status of the coral reef fish community dominating Darvel Bay as having undergone a rapid shift in structure following intense and rampant fishing pressure, as reported by the media.

Ask the Locals: A Community-Informed Analysis of Perceived Marine Environment Quality Over Time in Palawan, Philippines

Despite the potentially huge contributions that coastal communities might make in marine resource management and sustainability, their participation in such efforts have only been recognized recently, particularly in Southeast Asia. Involving community perceptions can offer new insights for policy makers and resource managers and can elicit strong commitment and support from the communities themselves. This article aims to understand the perceptions of coastal communities of local environmental issues, specifically how these have developed over time, to understand the expectations and perceptions of trends. Sixteen marine environmental issues were identified during stakeholder meetings in Palawan, Philippines. A co-developed survey was administered to 431 respondents from coastal communities in two municipalities (Taytay and Aborlan) and in the city of Puerto Princesa in Palawan. The results show variation in the perceptions and expectations across issues. We find that communities expect positive trends for mangrove coverage, beach tree cover, and seagrass coverage as well as for seaweed farming and quality of drinking water. The amount of plastic litter, wild fish and shellfish, and the severity of sewage pollution are perceived to get slightly worse. The aquaculture sector is expected to remain unchanged in the future as it had been in the past. We also find significant differences in how people from different areas of residence perceive their marine environment. In the discussion, we mapped these different community perceptions on existing policies and their implementation. We further recommend how community perceptions can be integrated into resource management and policy making in the future.

Fishery management in a marine protected area with compliance gaps: Socio-economic and biological insights as a first step on the path of sustainability

Overfishing is one of the main impacts on the marine environment and multiple-use Marine Protected Areas (MPAs) could be a useful tool to conserve biodiversity and promote sustainable resource exploitation. However, ensuring a high level of protection on the ground is a difficult task. This work contributes to the analysis of the causes at the root of MPAs' ineffectiveness by examining the management of Paracentrotus lividus fishery in an Italian MPA, employing a multidisciplinary approach built on biological and socio-economic competences. This sea urchin species has a determinant ecological role in structuring infralittoral benthic assemblages and is the most exploited echinoid in Europe. From 2010 to 2018, underwater sampling was conducted over 39 monitoring sites to define P. lividus spatial and temporal trends. Declared catches and semi-structured interviews with local stakeholders were used to define the socio-economical context, underline existing conflicts among them, as well as to trace the historical evolution of sea urchin fishery. The results show that the management of sea urchin fishery is not sustainable, primarily because of the stakeholders' non-compliance with the rules. P. lividus stock is progressively declining (-73% in 9 years), showing no difference between MPA (0.5 ± 0.15 ind./m²) and control sites (0.3 ± 0.04 ind./m²). Moreover, fishermen dominate the social arena while scientists, civil society and local press have little relevance. Additionally, the untruthfulness of catch declarations was proved, the IUU fishery is relevant and the black market is hiding the actual economic value. This work offers management solutions that may be useful in other areas that show similar compliance issues.

Direct and indirect effects of climate change-amplified pulse heat stress events on coral reef fish communities

Climate change-amplified temperature anomalies pose an imminent threat to coral reef ecosystems. While much focus has been placed on the effects of heat stress on scleractinian corals-including bleaching, mortality, and loss of reef structural complexity-and many studies have documented changes to reef fish communities arising indirectly from shifts in benthic composition, the direct impacts of heat stress on reef fish are much less well understood. Here, we quantify the direct and indirect effects of heat stress on reef fishes, using underwater visual censuses of coral reef fish communities conducted before, during, and after the 2015-2016 El Niño-induced global coral bleaching event. Surveys took place at the epicenter of this event, at 16 sites on Kiritimati (Republic of Kiribati; central equatorial Pacific) spanning across a gradient of local human disturbance. We expected that heat stress would have both direct and indirect negative effects on the reef fish community, with direct effects resulting from physiological stress during the event and indirect effects manifesting afterward as a consequence of coral mortality, and that the ability of fish communities to recover following the heat stress would depend on levels of local human disturbance. We found that total reef fish biomass and abundance declined by >50% during heat stress, likely as a result of vertical migration of fish to cooler waters. One year after the cessation of heat stress, however, total biomass, abundance, and species richness had recovered to, or even exceeded, pre-heat stress levels. However, the biomass of corallivores declined by over 70% following severe coral loss, and reefs exposed to higher levels of local human disturbance showed impaired recovery following the heat stress. These findings enhance understanding of the projected impacts of climate change-associated marine heatwaves on reef fishes, and highlight the interacting effects of local and global stressors on this vital component of coral reef ecosystems.

Illegal recreational fishing causes a decline in a fishery targeted species (Snapper: Chrysophrys auratus) within a remote no-take marine protected area

One role of Marine Protected Areas is to protect biodiversity; however, illegal fishing activity can reduce the effectiveness of protection. Quantifying illegal fishing effort within no-take MPAs is difficult and the impacts of illegal fishing on biodiversity are poorly understood. To provide an assessment of illegal fishing activity, a surveillance camera was deployed at the Seal Rocks no-take area within the Port Stephens-Great Lakes Marine Park from April 2017-March 2018. To assess impacts of illegal fishing activity in the no-take area, Baited Remote Underwater Video Systems (BRUVs) were used to quantify abundance and size of snapper Chrysophrys auratus from 2011-2017. BRUVs were also deployed at two nearby fished locations and two other no-take areas to allow comparison. Over 12 months of camera surveillance, a total of 108 recreational vessels were observed illegally fishing within the no-take area (avg 9.0 ± 0.9 per month). The greatest number of vessels detected in a single month was 14 and the longest a vessel was observed fishing was ~ 6 hours. From 2011-2017, the abundance of C. auratus within the Seal Rocks no-take area significantly declined by 55%, whilst the abundance within the other fished areas and no-take areas did not significantly decline over the same period. Lengths of C. auratus in the Seal Rocks no-take area were significantly smaller in 2017 compared to 2013 which was driven by a decline in the number of legal sized fish over 30 cm. Based on mean number of illegal fishers per vessel recorded in the no-take area, and an allowable bag limit of 10 C. auratus per person, it is possible that more than 2,000 C. auratus are removed annually from this no-take area. There is a strong likelihood that illegal recreational fishing is causing a reduction on a fishery targeted species within a no-take MPA and measures need to be implemented to reduce the ongoing illegal fishing pressure.

Modeling Reef Fish Biomass, Recovery Potential, and Management Priorities in the Western Indian Ocean

Fish biomass is a primary driver of coral reef ecosystem services and has high sensitivity to human disturbances, particularly fishing. Estimates of fish biomass, their spatial distribution, and recovery potential are important for evaluating reef status and crucial for setting management targets. Here we modeled fish biomass estimates across all reefs of the western Indian Ocean using key variables that predicted the empirical data collected from 337 sites. These variables were used to create biomass and recovery time maps to prioritize spatially explicit conservation actions. The resultant fish biomass map showed high variability ranging from ~15 to 2900 kg/ha, primarily driven by human populations, distance to markets, and fisheries management restrictions. Lastly, we assembled data based on the age of fisheries closures and showed that biomass takes ~ 25 years to recover to typical equilibrium values of ~1200 kg/ha. The recovery times to biomass levels for sustainable fishing yields, maximum diversity, and ecosystem stability or conservation targets once fishing is suspended was modeled to estimate temporal costs of restrictions. The mean time to recovery for the whole region to the conservation target was 8.1(± 3SD) years, while recovery to sustainable fishing thresholds was between 0.5 and 4 years, but with high spatial variation. Recovery prioritization scenario models included one where local governance prioritized recovery of degraded reefs and two that prioritized minimizing recovery time, where countries either operated independently or collaborated. The regional collaboration scenario selected remote areas for conservation with uneven national responsibilities and spatial coverage, which could undermine collaboration. There is the potential to achieve sustainable fisheries within a decade by promoting these pathways according to their social-ecological suitability.