Impact of marine protected areas on temporal stability of fish species diversity

Ecotoxicological impact of the fungicide tebuconazole on fish: a historical review, global trends and challenges

Tebuconazole (TBZ) is a triazole fungicide broadly used to control fungal diseases in agricultural crops, fruit-bearing plants and forestry plantations. However, its increasing use and release into aquatic environments has raised concerns about its hazardous effects on the health of fish. Thus, the aim of the present study was to review the scientific literature on the ecotoxicological effects of TBZ and TBZ-based commercial formulations on fish. Historical review data (publication year and geographical distribution), TBZ type, experimental design, fish species, habitat, life stage, tissue/organ, lethal concentration (LC50), concentration and exposure time, biomarkers and effects were compiled and critically analyzed. Studies were mainly conducted with freshwater species at adult and larval stages, whereas no data were find for marine fish species. Zebrafish, (Danio rerio) was the most assessed species. Both TBZ and TBZ-based commercial formulations induced oxidative stress, endocrine disruption, neurotoxicity, genotoxicity, histopathologies, behavior impairments and mortality on fish. TBZ can induce synergistic and antagonistic effects on fish when it is combined to other pesticides. Overall, the current study has shown the potential hazardous effects of TBZ and TBZ-based commercial formulations on the health of fish.

Environmental Gradients Linked to Human Impacts, Not Species Richness, Drive Regional Variation in Community Stability in Coral Reef Fishes

The stabilising effect of biodiversity on aggregate community properties is well-established experimentally, but its importance in naturally assembled communities at larger scales requires considering its covariation with other biotic and abiotic factors. Here, we examine the diversity-stability relationship in a 27-year coral reef fish time series at 39 reefs spanning 10° latitude on Australia's Great Barrier Reef. We find that an apparent relationship between species richness and synchrony of population fluctuations is driven by these two variables' covariation with proximity to coastal influences. Additionally, coral cover volatility destabilises fish assemblages by increasing average population variability but not synchrony, an effect mediated by changes in the intensity of density regulation in the fish community. Our findings indicate that these two environmental factors, both of which are strongly influenced by anthropogenic activity, impact community stability more than diversity does, but by distinct pathways reflecting different underlying community-dynamic processes.

M. The effectiveness of marine protected areas on the spatio-temporal patterns of reef fish in the Southwest Atlantic

This study explored spatio-temporal patterns influencing reef fish richness and abundance in two coastal islands within marine protected areas (MPAs) in southeastern Brazil. Data were collected using a remotely operated vehicle (ROV) during the 2022 seasonal cycle, with samples taken day and night. A total of 16 661 individuals from 81 species was recorded. The results showed that fish abundance was higher during the day, in winter and in areas with high temperatures. At night, in autumn, behavioural changes were observed in schooling species. Seasonal variations, including temperature changes and the oceanographic characteristics of the study area, influenced fish abundance and species composition, favouring tropical and subtropical species. Depth affected the islands differently: higher abundance was observed in deeper waters at Anchieta Island State Park, while shallower waters at Mar Virado Island showed greater abundance due to habitat complexity. Diurnal variation in richness was significant at Mar Virado Island, probably due to increased nocturnal predation. For fishing-targeted species, the islands showed significant effects on species composition and abundance, highlighting the importance of protected areas. The study offers key insights into reef fish dynamics, emphasizing the role of spatio-temporal variables in shaping communities and supporting conservation strategies in MPAs.

The ambiguous role of partially protected marine protected areas in Australia: Results from a systematic literature review

Marine protected areas (MPAs) are an important tool in helping to protect biodiversity in the oceans. Recent ratification of the Kunming-Montreal Global Biodiversity Framework (GBF) has ensured that globally we are committed to effectively protecting 30% of the world's oceans by 2030, in MPAs. In Australia there is considerable interest in the potential benefits that partially protected areas (PPAs) may provide. However, a consistent definition of a PPA is currently lacking, and urgently needed to conduct quantitative analyses of PPAs. We conducted a systematic literature review to understand the current knowledge surrounding PPAs and their potential benefits. We define a PPA, characterise PPA implementation in Australia, and present results for the outcomes of PPAs in terms of ecological, economic, and social indicators. Our review suggests that although 45% of Australia's marine environment is within MPAs, 61% of MPAs provide only partial protection. The Northern Territory (100%), New South Wales (81%), and Queensland (79.8%) have the highest percentage of MPAs that are partially protected, compared to Tasmania which has the smallest percentage of partially protected MPAs (13.12%). Tasmania also has the smallest percentage cover of MPAs (6.49% state waters). Most PPA management plans did not contain quantifiable Key Performance Indicators (KPIs) to be able to effectively monitor the progress of these PPAs against the stated outcomes. We find the benefits of PPAs to be ambiguous: PPAs generally provide benefits when compared to 'open' ocean, however this is not a consistent result. There are no PPAs that provide greater overall benefits when compared to fully protected MPAs. Only one state (South Australia) and the Commonwealth (Australian Marine Parks) are collecting publicly available baseline data to facilitate quantitative monitoring of PPAs. Contrary to fisheries management, there were no plans of action if the declared MPAs and PPAs failed to meet their declared objectives and goals. Some PPAs within Australia appear to be incompatible with conservation priorities according to the recent "MPA Guide" classification framework. This study highlights the need for clearer management rationale and plans for PPAs in Australia, as these comprise the majority of MPAs in Australia's Exclusive Economic Zone.

Marine protected areas promote stability of reef fish communities under climate warming

Protection from direct human impacts can safeguard marine life, yet ocean warming crosses marine protected area boundaries. Here, we test whether protection offers resilience to marine heatwaves from local to network scales. We examine 71,269 timeseries of population abundances for 2269 reef fish species surveyed in 357 protected versus 747 open sites worldwide. We quantify the stability of reef fish abundance from populations to metacommunities, considering responses of species and functional diversity including thermal affinity of different trophic groups. Overall, protection mitigates adverse effects of marine heatwaves on fish abundance, community stability, asynchronous fluctuations and functional richness. We find that local stability is positively related to distance from centers of high human density only in protected areas. We provide evidence that networks of protected areas have persistent reef fish communities in warming oceans by maintaining large populations and promoting stability at different levels of biological organization.

Reorganization of seagrass communities in a changing climate

Although climate change projections indicate significant threats to terrestrial biodiversity, the effects are much more profound and striking in the marine environment. Here we explore how different facets of locally distinctive α- and β-diversity (changes in spatial composition) of seagrasses will respond to future climate change scenarios across the globe and compare their coverage with the existing network of marine protected areas. By using species distribution modelling and a dated phylogeny, we predict widespread reductions in species' range sizes that will result in increases in seagrass weighted and phylogenetic endemism. These projected increases of endemism will result in divergent shifts in the spatial composition of β-diversity leading to differentiation in some areas and the homogenization of seagrass communities in other regions. Regardless of the climate scenario, the potential hotspots of these projected shifts in seagrass α- and β-diversity are predicted to occur outside the current network of marine protected areas, providing new priority areas for future conservation planning that incorporate seagrasses. Our findings report responses of species to future climate for a group that is currently under represented in climate change assessments yet crucial in maintaining marine food chains and providing habitat for a wide range of marine biodiversity.