A blueprint for national assessments of the blue carbon capacity of kelp forests applied to Canada's coastline.

Kelp forests offer substantial carbon fixation, with the potential to contribute to natural climate solutions (NCS). However, to be included in national NCS inventories, governments must first quantify the kelp-derived carbon stocks and fluxes leading to carbon sequestration. Here, we present a blueprint for assessing the national blue carbon capacity of kelp forests in which data synthesis and Bayesian hierarchical modeling enable estimates of kelp carbon production, storage, and export capacity from limited data.

Kelp forests as nursery and foundational habitat for reef fishes.

Conservation of marine biodiversity requires an understanding of the habitats needed to support and replenish species of interest. It also requires knowledge about the abundance and diversity of multispecies assemblages. Variation in the distribution and composition of kelp forests, one of the most productive marine coastal habitats globally, can have major influences on reef fishes-a group of ecologically and socioeconomically important species.

COVID-19 highlights the need to improve resilience and equity in managing small-scale fisheries.

The COVID-19 pandemic exposed the fragility of global and domestic seafood markets. We examined the main impacts and responses of the small-scale fisheries (SSF) sector, and found that mitigation and preparedness strategies should be prioritised to boost resilience in SSF. We provide five policy options and considerations: (1) improving access to insurance and financial services; (2) strengthening local and regional markets and supporting infrastructure; (3) recognising fisheries as an essential service; (4) integrating disaster risk management into fisheries management systems; and (5) investing in Indigenous and locally-led fisheries management.

Disrupting and diversifying the values, voices and governance principles that shape biodiversity science and management.

With climate, biodiversity and inequity crises squarely upon us, never has there been a more pressing time to rethink how we conceptualize, understand and manage our relationship with Earth's biodiversity. Here, we describe governance principles of 17 Indigenous Nations from the Northwest Coast of North America used to understand and steward relationships among all components of nature, including humans. We then chart the colonial origins of biodiversity science and use the complex case of sea otter recovery to illuminate how ancestral governance principles can be mobilized to characterize, manage and restore biodiversity in more inclusive, integrative and equitable ways.

Fish, People, and Systems of Power: Understanding and Disrupting Feedback between Colonialism and Fisheries Science.

AbstractThis essay explores shifting scientific understandings of fish and the evolution of fisheries science, and it grapples with colonialism as a system of power. We trace the rise of fisheries science to a time when Western nation-states were industrializing fishing fleets and competing for access to distant fishing grounds. A theory of fishing called "maximum sustainable yield" (MSY) that understands fish species in aggregate was espoused.

Improving the ability of a BACI design to detect impacts within a kelp-forest community.

Distinguishing between human impacts and natural variation in abundance remains difficult because most species exhibit complex patterns of variation in space and time. When ecological monitoring data are available, a before-after-control-impact (BACI) analysis can control natural spatial and temporal variation to better identify an impact and estimate its magnitude. However, populations with limited distributions and confounding spatial-temporal dynamics can violate core assumptions of BACI-type designs.

The impact of Hurricane Michael on longleaf pine habitats in Florida.

Global biodiversity hotspots (GBHs) are increasingly vulnerable to human stressors such as anthropogenic climate change, which will alter the ecology of these habitats, even where protected. The longleaf pine (Pinus palustris) ecosystem (LPE) of the North American Coastal Plain is a GBH where disturbances are integral for ecosystem maintenance. However, stronger storms due to climate change may be outside their historical norm.

Spatial variation in exploited metapopulations obscures risk of collapse.

Unanticipated declines among exploited species have commonly occurred despite harvests that appeared sustainable prior to collapse. This is particularly true in the oceans where spatial scales of management are often mismatched with spatially complex metapopulations. We explore causes, consequences, and potential solutions for spatial mismatches in harvested metapopulations in three ways.

Living coral tissue slows skeletal dissolution related to ocean acidification.

Climate change is causing major changes to marine ecosystems globally, with ocean acidification of particular concern for coral reefs. Using a 200 d in situ carbon dioxide enrichment study on Heron Island, Australia, we simulated future ocean acidification conditions, and found reduced pH led to a drastic decline in net calcification of living corals to no net growth, and accelerated disintegration of dead corals. Net calcification declined more severely than in previous studies due to exposure to the natural community of bioeroding organisms in this in situ study and to a longer experimental duration.

Sudden collapse of a mesopredator reveals its complementary role in mediating rocky reef regime shifts.

While changes in the abundance of keystone predators can have cascading effects resulting in regime shifts, the role of mesopredators in these processes remains underexplored. We conducted annual surveys of rocky reef communities that varied in the recovery of a keystone predator (sea otter, ) and the mass mortality of a mesopredator (sunflower sea star, ) due to an infectious wasting disease. By fitting a population model to empirical data, we show that sea otters had the greatest impact on the mortality of large sea urchins, but that decline corresponded to a 311% increase in medium urchins and a 30% decline in kelp densities.

Long-term increases in tropical flowering activity across growth forms in response to rising CO and climate change.

Mounting evidence suggests that anthropogenic global change is altering plant species composition in tropical forests. Fewer studies, however, have focused on long-term trends in reproductive activity, in part because of the lack of data from tropical sites. Here, we analyze a 28-year record of tropical flower phenology in response to anthropogenic climate and atmospheric change.

Sensitivity of sea urchin fertilization to pH varies across a natural pH mosaic.

In the coastal ocean, temporal fluctuations in pH vary dramatically across biogeographic ranges. How such spatial differences in pH variability regimes might shape ocean acidification resistance in marine species remains unknown. We assessed the pH sensitivity of the sea urchin in the context of ocean pH variability.

Global patterns of kelp forest change over the past half-century.

Kelp forests (Order Laminariales) form key biogenic habitats in coastal regions of temperate and Arctic seas worldwide, providing ecosystem services valued in the range of billions of dollars annually. Although local evidence suggests that kelp forests are increasingly threatened by a variety of stressors, no comprehensive global analysis of change in kelp abundances currently exists. Here, we build and analyze a global database of kelp time series spanning the past half-century to assess regional and global trends in kelp abundances.

Competition among Eggs Shifts to Cooperation along a Sperm Supply Gradient in an External Fertilizer.

Competition among gametes for fertilization imposes strong selection. For external fertilizers, this selective pressure extends to eggs for which spawning conditions can range from sperm limitation (competition among eggs) to sexual conflict (overabundance of competing sperm toxic to eggs). Yet existing fertilization models ignore dynamics that can alter the functional nature of gamete interactions.

Stochastic density effects on adult fish survival and implications for population fluctuations.

The degree to which population fluctuations arise from variable adult survival relative to variable recruitment has been debated widely for marine organisms. Disentangling these effects remains challenging because data generally are not sufficient to evaluate if and how adult survival rates are regulated by stochasticity and/or population density. Using unique time series for a largely unexploited reef fish, we found both population density and stochastic food supply impacted adult survival.

Fluctuations in food supply drive recruitment variation in a marine fish.

Reproductive rates and survival of young in animal populations figure centrally in generating management and conservation strategies. Model systems suggest that food supply can drive these often highly variable properties, yet for many wild species, quantifying such effects and assessing their implications have been challenging. We used spatially explicit time series of a well-studied marine reef fish (black surfperch Embiotoca jacksoni) and its known prey resources to evaluate the extent to which fluctuations in food supply influenced production of young by adults and survival of young to subadulthood.