• Energy Research

AbstractA variety of criteria may influence the efficacy of networks of marine protected areas (MPA) designed to enhance biodiversity conservation and provide fisheries benefits. Meta‐analyses have evaluated the influence of MPA attributes on abundance, biomass, and size structure of harvested species, reporting that MPA size, age, depth, and connectivity influence the strength of MPA responses. However, few empirical MPA evaluation studies have used consistent sampling methodology across multiple MPAs and years. Our collaborative fisheries research program systematically sampled 12 no‐take or highly protective limited‐take MPAs and paired fished reference areas across a network spanning 1100 km of coastline to evaluate the factors driving MPA efficacy across a large geographic region. We found that increased size and age consistently contributed to increased fish catch, biomass, and positive species responses inside MPAs, while accounting for factors such as latitude, primary productivity, and distance to the nearest MPA. Our study provides a model framework to collaboratively engage diverse stakeholders in fisheries research and provide high‐quality data to assess the success of conservation strategies.

Los bosques de algas marinas del sur de Sudamérica son algunos de los menos perturbados del planeta. La lejanía de esta región, hasta hace poco, la ha salvado de muchos de los factores estresantes antropogénicos directos que han afectado negativamente a estos ecosistemas en otros lugares. Las nuevas encuestas de 11 ubicaciones en la extensión más oriental de Tierra del Fuego realizadas originalmente en 1973 no mostraron diferencias significativas en las densidades de algas marinas Macrocystis pyrifera adultas y juveniles o diámetro de retención de algas marinas entre los dos períodos de encuesta. Además, la estructura del conjunto de erizos de mar en los mismos sitios no fue significativamente diferente entre los dos períodos de tiempo, con la especie dominante Loxechinus albus representando el 66.3% de la abundancia total de erizos de mar en 2018 y el 61.1% en 1973. Las series temporales de imágenes Landsat de la región de 1998 a 2018 no mostraron tendencias a largo plazo en el dosel de algas marinas en los últimos 20 años. Sin embargo, se observaron oscilaciones de ~ 4 años en la fracción del dosel y se correlacionaron fuerte y negativamente con el índice Enos multivariante de la NOAA y la temperatura de la superficie del mar. Una encuesta más extensa en 2018 mostró diferencias significativas en la estructura de la comunidad bentónica entre las ubicaciones expuestas y las protegidas. Las especies de peces endémicas de la Provincia de Magallanes representaron el 73% de todas las especies cercanas a la costa observadas y del 98–100% de la abundancia numérica enumerada en los sitios. La estructura del conjunto de peces varió significativamente entre las ubicaciones y las exposiciones a las olas. La reciente creación del Parque Marino de Yaganes es un paso importante en la protección de esta región única y biológicamente rica; sin embargo, las aguas cercanas a la costa de la región actualmente no están incluidas en esta protección. Existe una falta general de información sobre los cambios en los bosques de algas marinas durante largos períodos de tiempo, lo que dificulta una evaluación global. Una imagen completa de cómo estos ecosistemas están respondiendo a las presiones humanas también debe incluir ubicaciones remotas y ubicaciones con poco o ningún impacto. Les forêts de varech du sud de l'Amérique du Sud sont parmi les moins perturbées de la planète. L'éloignement de cette région l'a, jusqu'à récemment, épargnée de nombreux facteurs de stress anthropiques directs qui ont affecté négativement ces écosystèmes ailleurs. Les nouveaux relevés de 11 emplacements à l'extrémité est de la Terre de Feu, effectués initialement en 1973, n'ont montré aucune différence significative dans les densités de varech Macrocystis pyrifera adulte et juvénile ou dans le diamètre du support de varech entre les deux périodes de relevé. De plus, la structure d'assemblage des oursins sur les mêmes sites n'était pas significativement différente entre les deux périodes, l'espèce dominante Loxechinus albus représentant 66,3 % de l'abondance totale des oursins en 2018 et 61,1 % en 1973. Les séries chronologiques des images Landsat de la région de 1998 à 2018 n'ont montré aucune tendance à long terme du couvert de varech au cours des 20 dernières années. Cependant, des oscillations de ~ 4 ans dans la fraction de la canopée ont été observées et étaient fortement et négativement corrélées avec l'indice ENSO multivarié de la NOAA et la température de surface de la mer. Des études plus approfondies en 2018 ont montré des différences significatives dans la structure de la communauté benthique entre les zones exposées et les zones abritées. Les espèces de poissons endémiques de la province de Magellan représentaient 73 % de toutes les espèces côtières observées et de 98 à 100 % de l'abondance numérique dénombrée dans les sites. La structure de l'assemblage des poissons variait considérablement selon les emplacements et l'exposition aux vagues. La création récente du parc marin de Yaganes est une étape importante dans la protection de cette région unique et biologiquement riche ; cependant, les eaux côtières de la région ne sont actuellement pas incluses dans cette protection. Il existe un manque général d'informations sur les changements dans les forêts de varech sur de longues périodes, ce qui rend difficile une évaluation globale. Une image complète de la façon dont ces écosystèmes réagissent aux pressions humaines doit également inclure des endroits éloignés et des endroits avec peu ou pas d'impact. The kelp forests of southern South America are some of the least disturbed on the planet. The remoteness of this region has, until recently, spared it from many of the direct anthropogenic stressors that have negatively affected these ecosystems elsewhere. Re-surveys of 11 locations at the easternmost extent of Tierra del Fuego originally conducted in 1973 showed no significant differences in the densities of adult and juvenile Macrocystis pyrifera kelp or kelp holdfast diameter between the two survey periods. Additionally, sea urchin assemblage structure at the same sites were not significantly different between the two time periods, with the dominant species Loxechinus albus accounting for 66.3% of total sea urchin abundance in 2018 and 61.1% in 1973. Time series of Landsat imagery of the region from 1998 to 2018 showed no long-term trends in kelp canopy over the past 20 years. However, ~ 4-year oscillations in canopy fraction were observed and were strongly and negatively correlated with the NOAA Multivariate ENSO index and sea surface temperature. More extensive surveying in 2018 showed significant differences in benthic community structure between exposed and sheltered locations. Fish species endemic to the Magellanic Province accounted for 73% of all nearshore species observed and from 98–100% of the numerical abundance enumerated at sites. Fish assemblage structure varied significantly among locations and wave exposures. The recent creation of the Yaganes Marine Park is an important step in protecting this unique and biologically rich region; however, the nearshore waters of the region are currently not included in this protection. There is a general lack of information on changes in kelp forests over long time periods, making a global assessment difficult. A complete picture of how these ecosystems are responding to human pressures must also include remote locations and locations with little to no impact. تعد غابات عشب البحر في جنوب أمريكا الجنوبية من أقل الغابات إزعاجًا على هذا الكوكب. وقد أدى بعد هذه المنطقة، حتى وقت قريب، إلى تجنيبها العديد من الضغوطات البشرية المباشرة التي أثرت سلبًا على هذه النظم الإيكولوجية في أماكن أخرى. أظهرت عمليات إعادة مسح 11 موقعًا في أقصى شرق تييرا ديل فويغو التي أجريت في الأصل في عام 1973 عدم وجود اختلافات كبيرة في كثافة عشب البحر ماكروسيستيس بيريفيرا البالغ واليافع أو قطر عشب البحر بين فترتي المسح. بالإضافة إلى ذلك، لم يكن هيكل تجميع قنفذ البحر في نفس المواقع مختلفًا بشكل كبير بين الفترتين الزمنيتين، حيث شكل النوع السائد Loxechinus albus 66.3 ٪ من إجمالي وفرة قنفذ البحر في عام 2018 و 61.1 ٪ في عام 1973. لم تظهر السلاسل الزمنية لصور لاندسات للمنطقة من عام 1998 إلى عام 2018 أي اتجاهات طويلة الأجل في مظلة عشب البحر على مدى السنوات العشرين الماضية. ومع ذلك، لوحظت تذبذبات لمدة 4 سنوات تقريبًا في جزء المظلة وارتبطت ارتباطًا قويًا وسلبيًا بمؤشر ENSO متعدد المتغيرات التابع للإدارة الوطنية للمحيطات والغلاف الجوي (NOAA) ودرجة حرارة سطح البحر. أظهر مسح أكثر شمولاً في عام 2018 اختلافات كبيرة في بنية المجتمع القاعي بين المواقع المكشوفة والمحمية. شكلت أنواع الأسماك المستوطنة في مقاطعة ماجلان 73 ٪ من جميع الأنواع القريبة من الشاطئ التي تمت ملاحظتها ومن 98-100 ٪ من الوفرة العددية التي تم تعدادها في المواقع. اختلف هيكل تجمعات الأسماك بشكل كبير بين المواقع والتعرض للموجات. يعد إنشاء متنزه ياجانيس البحري مؤخرًا خطوة مهمة في حماية هذه المنطقة الفريدة والغنية بيولوجيًا ؛ ومع ذلك، فإن المياه القريبة من الشاطئ في المنطقة غير مدرجة حاليًا في هذه الحماية. هناك نقص عام في المعلومات حول التغيرات في غابات عشب البحر على مدى فترات زمنية طويلة، مما يجعل التقييم العالمي صعبًا. يجب أن تشمل الصورة الكاملة لكيفية استجابة هذه النظم الإيكولوجية للضغوط البشرية أيضًا المواقع النائية والمواقع ذات التأثير الضئيل أو المعدوم.

In ecosystems, sharks can be predators, competitors, facilitators, nutrient transporters, and food. However, overfishing and other threats have greatly reduced shark populations, altering their roles and effects on ecosystems. We review these changes and implications for ecosystem function and management. Macropredatory sharks are often disproportionately affected by humans but can influence prey and coastal ecosystems, including facilitating carbon sequestration. Like terrestrial predators, sharks may be crucial to ecosystem functioning under climate change. However, large ecosystem effects of sharks are not ubiquitous. Increasing human uses of oceans are changing shark roles, necessitating management consideration. Rebuilding key populations and incorporating shark ecological roles, including less obvious ones, into management efforts are critical for retaining sharks’ functional value. Coupled social-ecological frameworks can facilitate these efforts.

Global climate change increasingly contributes to large changes in ecosystem structure. Timely management of rapidly changing marine ecosystems must be matched with methods to rapidly quantify and assess climate driven impacts to ecological communities. Here we create a species-specific, classification system for fish thermal affinities, using three quantifiable datasets and expert opinion. Multiple sources of information limit potential data bias and avoid misclassification. Using a temperate kelp forest fish community in California, USA as a test case for this new methodology, we found the majority of species had high classification agreement across all four data sources (n = 78) but also a number of low agreement species (2 sources disagree from the others, n = 47). For species with low agreement, use of just one dataset to classify species, as is commonly done, would lead to high risk of misclassification. Differences in species classification between individual datasets and our composite classification were apparent. Applying different thermal classifications, lead to different conclusions when quantifying ‘warm’ and ‘cool’ species density responses to a marine heatwave. Managers can use this classification approach as a tool to generate accurate, timely and simple information for resource management.

The amount of ocean protected from fishing and other human impacts has often been used as a metric of conservation progress. However, protection efforts have highly variable outcomes that depend on local conditions, which makes it difficult to quantify what coral reef protection efforts to date have actually achieved at a global scale. Here, we develop a predictive model of how local conditions influence conservation outcomes on ~2,600 coral reef sites across 44 ecoregions, which we used to quantify how much more fish biomass there is on coral reefs compared to a modeled scenario with no protection. Under the assumptions of our model, our study reveals that without existing protection efforts there would be ~10% less fish biomass on coral reefs. Thus, we estimate that coral reef protection efforts have led to approximately 1 in every 10 kg of existing fish biomass.

AbstractMarine protected areas (MPAs) have gained attention as a conservation tool for enhancing ecosystem resilience to climate change. However, empirical evidence explicitly linking MPAs to enhanced ecological resilience is limited and mixed. To better understand whether MPAs can buffer climate impacts, we tested the resistance and recovery of marine communities to the 2014–2016 Northeast Pacific heatwave in the largest scientifically designed MPA network in the world off the coast of California, United States. The network consists of 124 MPAs (48 no‐take state marine reserves, and 76 partial‐take or special regulation conservation areas) implemented at different times, with full implementation completed in 2012. We compared fish, benthic invertebrate, and macroalgal community structure inside and outside of 13 no‐take MPAs across rocky intertidal, kelp forest, shallow reef, and deep reef nearshore habitats in California's Central Coast region from 2007 to 2020. We also explored whether MPA features, including age, size, depth, proportion rock, historic fishing pressure, habitat diversity and richness, connectivity, and fish biomass response ratios (proxy for ecological performance), conferred climate resilience for kelp forest and rocky intertidal habitats spanning 28 MPAs across the full network. Ecological communities dramatically shifted due to the marine heatwave across all four nearshore habitats, and MPAs did not facilitate habitat‐wide resistance or recovery. Only in protected rocky intertidal habitats did community structure significantly resist marine heatwave impacts. Community shifts were associated with a pronounced decline in the relative proportion of cold water species and an increase in warm water species. MPA features did not explain resistance or recovery to the marine heatwave. Collectively, our findings suggest that MPAs have limited ability to mitigate the impacts of marine heatwaves on community structure. Given that mechanisms of resilience to climate perturbations are complex, there is a clear need to expand assessments of ecosystem‐wide consequences resulting from acute climate‐driven perturbations, and the potential role of regulatory protection in mitigating community structure changes.