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Remote coral reefs are thought to be more resilient to climate change due to their isolation from local stressors like fishing and pollution. We tested this hypothesis by measuring the relationship between local human influence and coral community resilience. Surprisingly, we found no relationship between human influence and resistance to disturbance and some evidence that areas with greater human development may recover from disturbance faster than their more isolated counterparts. Our results suggest remote coral reefs are imperiled by climate change, like so many other geographically isolated ecosystems, and are unlikely to serve as effective biodiversity arks. Only drastic and rapid cuts in greenhouse gas emissions will ensure coral survival. Our results also indicate that some reefs close to large human populations were relatively resilient. Focusing research and conservation resources on these more accessible locations has the potential to provide new insights and maximize conservation outcomes.

 

Increased standing macroalgal biomass in upwelling zones is generally assumed to be the result of higher nutrient flux due to upwelled waters. However, other factors can strongly impact macroalgal communities. For example, herbivory and temperature, via their effects on primary producers and the metabolic demands of consumers, can also influence macroalgal biomass and productivity, respectively. We assessed the effects of nutrient availability, temperature, and herbivory on macroalgal biomass on a subtidal nearshore rocky reef in the Galápagos Islands. We manipulated nutrient availability and herbivory in field experiments performed in two seasons: the first during a cool, upwelling season, and the second during a warm, non-upwelling season. Excluding macro-herbivores had a clear effect on standing macroalgal biomass, independent of season or nutrient availability. However, we found different interactive effects of nutrients and macro-herbivores between the two seasons. During the cool season, macroalgal biomass was significantly higher in herbivore exclusions than in open areas under ambient nutrient conditions. However, when nutrients were added, macroalgal biomass was not significantly different across all herbivore treatments, which suggests reduced top-down control of herbivores (hence a greater standing algal biomass) in open areas. In the warm season, macroalgal biomass was significantly higher in herbivore exclusions compared to open treatments, both with and without nutrient addition. Furthermore, biomass reached 11X in herbivore exclusions with nutrient additions, which hints nutrient limitation only during warm, low-upwelling conditions. Overall, our results support the hypothesis that macro-herbivores reduce macroalgal biomass in this system and suggest that nutrient availability, but not temperature, modulate herbivory. 

Abstract The benthic marine algae of the mainland coast of Ecuador are poorly known mainly due to a lack of collections. Currently, DNA barcoding is the preferred method to identify species of benthic marine algae worldwide, as morpho-anatomical characters are inadequate to distinguish many species of macroalgae. We used the red algal barcode rbc L-3P to identify specimens collected in January 2020 from Manabí, Ecuador as Neoizziella asiatica . This is the first member of the red algal order Nemaliales to be reported from the mainland coast of Ecuador and extends the distribution of this alga by 1,100 km to the south from Panama. 

The world’s oceans are warming at an unprecedented rate, causing dramatic changes to coastal marine systems, especially coral reefs. We used three complementary ocean temperature databases (HadISST, Pathfinder, and OISST) to quantify change in thermal characteristics of Caribbean coral reefs over the last 150 years (1871–2020). These sea surface temperature (SST) databases included in situ and satellite-derived measurements at multiple spatial resolutions. We also compiled a Caribbean coral reef database identifying 5,326 unique reefs across the region. We found that Caribbean reefs have been warming for at least a century. Regionally reef warming began in 1915, and for four of the eight Caribbean ecoregions we assessed, significant warming was detected for the latter half of the nineteenth century. Following the global mid-twentieth century stasis, warming resumed on Caribbean reefs in the early 1980s in some ecoregions and in the 1990s for others. On average, Caribbean reefs warmed by 0.18°C per decade during this period, ranging from 0.17°C per decade on Bahamian reefs (since 1988) to 0.26°C per decade on reefs within the Southern and Eastern Caribbean ecoregions (since 1981 and 1984, respectively). If this linear rate of warming continues, these already threatened ecosystems would warm by an additional ~1.5°C on average by 2100. We also found that marine heatwave (MHW) events are increasing in both frequency and duration across the Caribbean. Caribbean coral reefs now experience on average 5 MHW events annually, compared to 1 per year in the early 1980s, with recent events lasting on average 14 days. These changes in the thermal environment, in addition to other stressors including fishing and pollution, have caused a dramatic shift in the composition and functioning of Caribbean coral reef ecosystems. 

DNA sequencing of the plastid encoded rbcL gene supported by morpho-anatomical features reveals Gracilaria parva sp. nov. from Panama and Ecuador in the tropical eastern Pacific Ocean. In the rbcL phylogram, G. parva occurs in a clade sister to the western Atlantic species G. galatensis. Morphologically and anatomically, G. parva is distinguished from two similar, described tropical eastern Pacific species, G. brevis and G. veleroae by its small size, to 2.5 cm tall with branch widths mostly <2 mm occasionally to 4 mm, and by its two to three cell layered cortex. Gracilaria brevis and G. veleroae are taller, have wider branches, and a one cell layered cortex. DNA sequencing is needed to resolve the many diminutive species in the tropical eastern Pacific, particularly those occurring in turf communities. DNA sequencing of historical type specimens from the 19th and 20th centuries is also needed to correctly apply names in this region. 

Disease, storms, ocean warming, and pollution have caused the mass mortality of reef-building corals across the Caribbean over the last four decades. Subsequently, stony corals have been replaced by macroalgae, bacterial mats, and invertebrates including soft corals and sponges, causing changes to the functioning of Caribbean reef ecosystems. Here we describe changes in the absolute cover of benthic reef taxa, including corals, gorgonians, sponges, and algae, at 15 fore-reef sites (12–15m depth) across the Belizean Barrier Reef (BBR) from 1997 to 2016. We also tested whether Marine Protected Areas (MPAs), in which fishing was prohibited but likely still occurred, mitigated these changes. Additionally, we determined whether ocean-temperature anomalies (measured via satellite) or local human impacts (estimated using the Human Influence Index, HII) were related to changes in benthic community structure. We observed a reduction in the cover of reef-building corals, including the long-lived, massive corals Orbicella spp. (from 13 to 2%), and an increase in fleshy and corticated macroalgae across most sites. These and other changes to the benthic communities were unaffected by local protection. The covers of hard-coral taxa, including Acropora spp., Montastraea cavernosa , Orbicella spp., and Porites spp., were negatively related to the frequency of ocean-temperature anomalies. Only gorgonian cover was related, negatively, to our metric of the magnitude of local impacts (HII). Our results suggest that benthic communities along the BBR have experienced disturbances that are beyond the capacity of the current management structure to mitigate. We recommend that managers devote greater resources and capacity to enforcing and expanding existing marine protected areas and to mitigating local stressors, and most importantly, that government, industry, and the public act immediately to reduce global carbon emissions. 

A substantial portion of seafood is mislabeled, causing significant impacts to human health, the environment, the economy, and society. Despite the large scientific literature documenting seafood mislabeling the public’s awareness of seafood mislabeling is unknown. We conducted an online survey to assess the public’s awareness and perceptions of seafood mislabeling. Of the 1,216 respondents, 38% had never heard of seafood mislabeling and 49% were only ‘vaguely familiar’ with it. After being provided the definition of seafood mislabeling 95% had some degree of concern. Respondents were the most concerned about environmental impacts caused by seafood mislabeling and the least concerned about the social justice implications. Respondents who were also more concerned and familiar with seafood mislabeling stated that they would be more likely to purchase seafood from a vendor where the labeling was independently verified.