Global floating kelp forests have limited protection despite intensifying marine heatwave threats.

Kelp forests are one of the earth's most productive ecosystems and are at great risk from climate change, yet little is known regarding their current conservation status and global future threats. Here, by combining a global remote sensing dataset of floating kelp forests with climate data and projections, we find that exposure to projected marine heatwaves will increase ~6 to ~16 times in the long term (2081-2100) compared to contemporary (2001-2020) exposure. While exposure will intensify across all regions, some southern hemisphere areas which have lower exposure to contemporary and projected marine heatwaves may provide climate refugia for floating kelp forests.

Evidence of spillover benefits from large-scale marine protected areas to purse seine fisheries.

Global tuna fisheries are valued at more than $40 billion, with the majority of this value derived from purse seine fisheries. Recently created large-scale marine protected areas are potentially big enough to protect highly migratory species such as tuna, possibly leading to increases in abundance (a conservation benefit) and consequent spillover near protected area boundaries (an economic benefit). Using publicly available data from nine large-scale marine protected areas across the Pacific and Indian oceans, we find that catch-per-unit-effort in tuna purse seine fisheries has increased by an average of 12 to 18% near protected area boundaries, and this increase declines with distance from the boundaries.

Marine Protected Areas That Preserve Trophic Cascades Promote Resilience of Kelp Forests to Marine Heatwaves.

Under accelerating threats from climate-change impacts, marine protected areas (MPAs) have been proposed as climate-adaptation tools to enhance the resilience of marine ecosystems. Yet, debate persists as to whether and how MPAs may promote resilience to climate shocks. Here, we use 38 years of satellite-derived kelp cover to empirically test whether a network of 58 temperate coastal MPAs in Central and Southern California enhances the resistance of kelp forest ecosystems to, and their recovery from, the unprecedented 2014-2016 marine heatwave regime that occurred in the region.

Whales in the carbon cycle: can recovery remove carbon dioxide?

The great whales (baleen and sperm whales), through their massive size and wide distribution, influence ecosystem and carbon dynamics. Whales directly store carbon in their biomass and contribute to carbon export through sinking carcasses. Whale excreta may stimulate phytoplankton growth and capture atmospheric CO; such indirect pathways represent the greatest potential for whale-carbon sequestration but are poorly understood.

Impact of two of the world's largest protected areas on longline fishery catch rates.

Two of the largest protected areas on earth are U.S. National Monuments in the Pacific Ocean.

An interdisciplinary evaluation of community-based TURF-reserves.

Coastal marine ecosystems provide livelihoods for small-scale fishers and coastal communities around the world. Small-scale fisheries face great challenges since they are difficult to monitor, enforce, and manage, which may lead to overexploitation. Combining territorial use rights for fisheries (TURF) with no-take marine reserves to create TURF-reserves can improve the performance of small-scale fisheries by buffering fisheries from environmental variability and management errors, while ensuring that fishers reap the benefits of conservation investments.

Spatial variation in allometric growth of invasive lionfish has management implications.

Lionfish () are an invasive species in the Western Atlantic and the Caribbean. Improving management of invasive lionfish populations requires accurate total biomass estimates, which depend on accurate estimates of allometric growth; sedentary species like lionfish often exhibit high levels of spatial variation in life history characteristics. We reviewed 17 published length-weight relationships for lionfish taken throughout their invasive range and found regional differences that led to significant misestimates when calculating weight from length observations.

A user-friendly tool to evaluate the effectiveness of no-take marine reserves.

Marine reserves are implemented to achieve a variety of objectives, but are seldom rigorously evaluated to determine whether those objectives are met. In the rare cases when evaluations do take place, they typically focus on ecological indicators and ignore other relevant objectives such as socioeconomics and governance. And regardless of the objectives, the diversity of locations, monitoring protocols, and analysis approaches hinder the ability to compare results across case studies.