Continent-wide declines in shallow reef life over a decade of ocean warming.

Human society is dependent on nature1,2, but whether our ecological foundations are at risk remains unknown in the absence of systematic monitoring of species' populations3. Knowledge of species fluctuations is particularly inadequate in the marine realm4. Here we assess the population trends of 1,057 common shallow reef species from multiple phyla at 1,636 sites around Australia over the past decade. Most populations decreased over this period, including many tropical fishes, temperate invertebrates (particularly echinoderms) and southwestern Australian macroalgae, whereas coral populations remained relatively stable. Population declines typically followed heatwave years, when local water temperatures were more than 0.5 °C above temperatures in 2008. Following heatwaves5,6, species abundances generally tended to decline near warm range edges, and increase near cool range edges. More than 30% of shallow invertebrate species in cool latitudes exhibited high extinction risk, with rapidly declining populations trapped by deep ocean barriers, preventing poleward retreat as temperatures rise. Greater conservation effort is needed to safeguard temperate marine ecosystems, which are disproportionately threatened and include species with deep evolutionary roots. Fundamental among such efforts, and broader societal needs to efficiently adapt to interacting anthropogenic and natural pressures, is greatly expanded monitoring of species' population trends7,8.

Tracking widespread climate-driven change on temperate and tropical reefs.

Warming seas, marine heatwaves, and habitat degradation are increasingly widespread phenomena affecting marine biodiversity, yet our understanding of their broader impacts is largely derived from collective insights from independent localized studies. Insufficient systematic broadscale monitoring limits our understanding of the true extent of these impacts and our capacity to track these at scales relevant to national policies and international agreements. Using an extensive time series of co-located reef fish community structure and habitat data spanning 12 years and the entire Australian continent, we found that reef fish community responses to changing temperatures and habitats are dynamic and widespread but regionally patchy. Shifts in composition and abundance of the fish community often occurred within 2 years of environmental or habitat change, although the relative importance of these two mechanisms of climate impact tended to differ between tropical and temperate zones. The clearest of these changes on temperate and subtropical reefs were temperature related, with responses measured by the reef fish thermal index indicating reshuffling according to the thermal affinities of species present. On low latitude coral reefs, the community generalization index indicated shifting dominance of habitat generalist fishes through time, concurrent with changing coral cover. Our results emphasize the importance of maintaining local ecological detail when scaling up datasets to inform national policies and global biodiversity targets. Scaled-up ecological monitoring is needed to discriminate among increasingly diverse drivers of large-scale biodiversity change and better connect presently disjointed systems of biodiversity observation, indicator research, and governance.

Evaluating the social and ecological effectiveness of partially protected marine areas.

Marine protected areas (MPAs) are a primary tool for the stewardship, conservation, and restoration of marine ecosystems, yet 69% of global MPAs are only partially protected (i.e., are open to some form of fishing). Although fully protected areas have well-documented outcomes, including increased fish diversity and biomass, the effectiveness of partially protected areas is contested. Partially protected areas may provide benefits in some contexts and may be warranted for social reasons, yet social outcomes often depend on MPAs achieving their ecological goals to distinguish them from open areas and justify the cost of protection. We assessed the social perceptions and ecological effectiveness of 18 partially protected areas and 19 fully protected areas compared with 19 open areas along 7000 km of coast of southern Australia. We used mixed methods, gathering data via semistructured interviews, site surveys, and Reef Life (underwater visual census) surveys. We analyzed qualitative data in accordance with grounded theory and quantitative data with multivariate and univariate linear mixed-effects models. We found no social or ecological benefits for partially protected areas relative to open areas in our study. Partially protected areas had no more fish, invertebrates, or algae than open areas; were poorly understood by coastal users; were not more attractive than open areas; and were not perceived to have better marine life than open areas. These findings provide an important counterpoint to some large-scale meta-analyses that conclude partially protected areas can be ecologically effective but that draw this conclusion based on narrower measures. We argue that partially protected areas act as red herrings in marine conservation because they create an illusion of protection and consume scarce conservation resources yet provide little or no social or ecological gain over open areas. Fully protected areas, by contrast, have more fish species and biomass and are well understood, supported, and valued by the public. They are perceived to have better marine life and be improving over time in keeping with actual ecological results. Conservation outcomes can be improved by upgrading partially protected areas to higher levels of protection including conversion to fully protected areas.

Análisis de la Efectividad Social y Ecológica de las Áreas Marinas Parcialmente Protegidas Resumen Las áreas marinas protegidas (AMPs) son una herramienta importante para la administración, conservación y restauración de los ecosistemas marinos; sin embargo, el 69% de las AMPs mundiales solamente están parcialmente protegidas (es decir, están abiertas a alguna forma de pesca). Aunque las áreas completamente protegidas tienen resultados bien documentados, incluyendo el incremento en la diversidad de peces y la biomasa, la efectividad de las áreas parcialmente protegidas está en disputa. Puede que las áreas parcialmente protegidas se justifiquen por razones sociales, aunque los resultados sociales con frecuencia dependen de que las AMPs alcancen sus metas ecológicas para distinguirlas de las áreas abiertas y justificar el costo de la protección. Analizamos las percepciones sociales y la efectividad ecológica de 18 áreas parcialmente protegidas y 19 áreas completamente protegidas a lo largo de 7000 km de costa en el sur de Australia. Usamos métodos mixtos, recopilando información por medio de entrevistas semiestructuradas, encuestas en sitio y censos Reef Life (censos visuales submarinos). Analizamos los datos cualitativos de acuerdo con la teoría fundamentada y los datos cuantitativos con modelos lineales de efectos mixtos multivariados y univariados. No encontramos beneficios sociales o ecológicos para las áreas parcialmente protegidas en relación con las áreas abiertas en nuestro estudio. Las áreas parcialmente protegidas no tuvieron más peces, invertebrados o algas que las áreas abiertas; los usuarios de la costa tenían poco entendimiento de ellas; no eran más atractivas que las áreas abiertas; y no eran percibidas como albergues de mejor vida marina que las áreas abiertas. Estos hallazgos proporcionan un contrapunto importante a algunos metaanálisis a gran escala que concluyen que las áreas parcialmente protegidas pueden ser ecológicamente efectivas, pero llegan a esta conclusión con base en medidas más reducidas. Discutimos que las áreas parcialmente protegidas funcionan como pistas falsas para la conservación marina pues crean una ilusión de estar protegidas y consumen pocos recursos para la conservación, pero proporcionan poca o ninguna ganancia ecológica o social en comparación con las áreas abiertas. Las áreas completamente protegidas, al contrario, tienen más especies de peces y biomasa y están bien comprendidas, respaldadas y valoradas por el público. Este tipo de AMPs son percibidas como albergues de mejor vida marina y como en constante mejora con el tiempo al mantenerse en regla con los resultados ecológicos actuales. Los resultados de la conservación pueden mejorarse si se eleva a las áreas parcialmente protegidas a niveles más altos de protección incluyendo la conversión a áreas completamente protegidas.

LESI: A quantitative indicator to measure local environmental stewardship.

This method develops a local environmental stewardship indicator (LESI), which represents the level of stewardship action of a person at a place. The goal of the indicator is to quantify stewardship activity and allow it to be compared and modelled. LESI requires a brief interview to ascertain an individual's past and current stewardship activities, which are scored on a frequency scale for each of seven action categories. Scores are then combined using the LESI equation to: • Quantify reported stewardship behaviour (as opposed to attitudes or intentions) as a single number. • Enable comparisons of stewardship between individuals and places. • Allow development of models to understand the predictors of stewardship, and • Inform evidence-based strategies for stewardship improvement.