Not all waves are created equal

Not all waves are created equal

Why do some big wave events swamp Kiribati’s Tarawa lagoon shorelines while others pound the windward coast? A new UBC-led study disentangles the culprits and shows why future flooding risk will not be uniform across the atoll.

After analyzing 40 years of offshore wave varieties hitting the Tarawa atoll from 1979 to 2018, including 41 extreme events, it was found that when elevated water levels and the right wave direction line up, inundation risk jumps. This is particularly true during El Niño, when regional sea level sits higher.

Photograph depicting wave impact on the lagoon-facing shoreline in Bikenibeu, Tarawa, on February 24, 2005. Photo: Julia Mayer

Photograph depicting wave impact on the lagoon-facing shoreline in Bikenibeu, Tarawa, on February 24, 2005. Photo: Julia Mayer

“Tarawa offers us a broader lesson for low lying atolls across the Pacific,” said Julia Mayer, PhD student in UBC’s Institute for the Oceans and Fisheries, and first author on the study. “Not all extremes arrive in the same way. As sea levels rise, extreme wave events, especially those linked to El Niño conditions, are expected to become more destructive for the people of Tarawa.”

Damage to the Arorae maneaba on the lagoon-facing shoreline of Bairiki, Tarawa from the March 2014 inundation event. The photo was taken in May 2014. Photo: Julia Mayer

Damage to the Arorae maneaba on the lagoon-facing shoreline of Bairiki, Tarawa from the March 2014 inundation event. The photo was taken in May 2014. Photo: Julia Mayer

Instead of treating big waves as one hazard, the team used hierarchical clustering to group extreme days by full frequency and direction fingerprints. This linked each cluster to different atmospheric triggers and specific coastlines at risk. They identified three event types that drive extremes in Tarawa: first, El Niño related westerly wind bursts that whip up locally generated lagoon waves; second, long period swells from the south and southwest produced by Southern Hemisphere storm; and finally, swells from the north and northeast tied to Northern Hemisphere storms.

“Our results upended the common assumption that open ocean shores are always most vulnerable. Some of the most damaging events were the result of wind reversals during El Niño,” said Mayer. “The atoll’s partially open lagoon generated energetic waves that pushed water toward low lying, populated shorelines. Places that usually enjoy lower wave energy can become hotspots of risk.”

“Tarawa is a thriving place, the capital of the country, and one of the more densely populated atolls in the world,” said Dr. Simon Donner, senior author on the paper and professor in the IOF, as well as UBC’s Institute for Resources, Environment and Sustainability, and Department of Geography. “The rising population has led to more and more people living in marginal lands that at vulnerable to waves and flooding”.

“Sea-level rise is an existential threat to places like Tarawa. The islands may not ‘disappear’, as is often reported, but they will become increasingly challenging places to live. A better understanding of what drives high wave events can help inform adaptation planning and keep communities safe,” Donner said.

For Tarawa, and many atolls, the big question is not only how big the waves are. “It is which waves, when they arrive, and how high the ocean sits beneath them,” Mayer concluded.

“Clustering of Historical Extreme Wave Events to Assess Climate Variability in Tarawa Atoll, Republic of Kiribati” was published in Natural Hazards.

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Dr. Rashid Sumaila appointed to the Nature Conservancy’s Global Board of Directors

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Breaking down research silos to understand a shifting Salish Sea

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Orcas and dolphins seen hunting together for the first time

For the first time, killer whales and dolphins were seen teaming up to hunt salmon off B.C.’s coast—a surprising alliance that could reshape our understanding of marine predators. Read how researchers uncovered this extraordinary partnership.

Dolphin with a pod of northern resident killer whales. Credit: University of British Columbia (A. Trites), Dalhousie University (S. Fortune), Hakai Institute (K. Holmes), Leibniz Institute for Zoo and Wildlife Research (X. Cheng)

Dolphin with a pod of northern resident killer whales. Credit: University of British Columbia (A. Trites), Dalhousie University (S. Fortune), Hakai Institute (K. Holmes), Leibniz Institute for Zoo and Wildlife Research (X. Cheng).

Canadian researchers capture rare video of killer whales and dolphins working together to forage salmon off B.C. coast, suggesting the two species have forged a co-operative relationship

A new study has revealed that two top ocean predators—northern resident killer whales and Pacific white-sided dolphins—join forces to find and feast on salmon off B.C., with the first video of its kind showing the two species hunting for food and suggesting they have forged a co-operative relationship that may provide mutual benefits.  

The paper, published today in the journal Scientific Reports, was undertaken by researchers from UBC, Dalhousie University, the Leibniz Institute, and the Hakai Institute, and shows that these interactions are not just chance encounters. Instead, the species appear to be working together to hunt Chinook salmon in waters off B.C., where they are often seen within metres of each other.  

“We’ve long known that resident killer whales interact with Pacific white-sided dolphins, but seeing them dive and hunt in sync with dolphins completely changes our understanding of what those encounters mean,” said lead author Dr. Sarah Fortune, Canadian Wildlife Federation Chair in Large Whale Conservation and assistant professor in Dalhousie’s oceanography department.  

“Our footage shows that killer whales and dolphins may actually be cooperating to find and share prey—something never before documented in this population.” 

Using drones launched by the Hakai Institute and suction-cup biologging tags that later fell off, researchers captured remarkable aerial and underwater footage of the animal’s co-ordinated interactions. 

The observations showed that the two species frequently foraged in close proximity and often synchronized their movements. Killer whales were seen orienting toward dolphins and following them to depth, suggesting the whales were eavesdropping and using dolphin echolocation cues to help locate the large salmon—prey that dolphins cannot capture and swallow whole.  

“The strategic alliance we observed between the dolphins and killer whales is extraordinary,” said senior author Dr. Andrew Trites, a professor and director of the Marine Mammal Research Unit at UBC’s Institute for the Oceans and Fisheries.  

The videos reveal that once whales caught their prey and broke them apart into smaller pieces to share with other killer whales, the dolphins were quick to scavenge the leftovers.  

“By working together, killer whales can conserve energy and use the dolphins as radar-equipped scouts to increase their chances of finding large Chinook salmon at deeper depths. In return, the dolphins gain predator protection and access to scraps from one of the ocean’s most prized fish. It’s a win-win for everyone involved.”  

Keith Holmes, a drone pilot with the Hakai Institute, first spotted the behaviour by chance during fieldwork for a UBC-led project. “From above you could see this incredible amount of activity. It was clear that there was some sort of communication happening and they were actively foraging together.”  

The team, which conducted the work in the north island waters of Vancouver Island in August 2020, used long carbon fibre poles to temporarily attach suction-cup tags to whales they identified by their unique markings, with only animals in good health that also weren’t pregnant or lactating, selected for tagging.  

It was the first time Customized Animal Tracking Solutions Tags (CATS) were used on whales and allowed the researchers to collect 3D kinematic data with video and acoustics, continuously recording high-resolution dive data, along with vocalizations and feeding-related sounds.  

The researchers recorded 258 unique events of dolphins traveling near the head of tagged killer whales.  All of the whales that interacted with dolphins engaged in foraging-related behaviours, such as killing,  eating and searching for the salmon. Notably, the two species showed no signs of aggressive or avoidant behaviour. 

The findings highlight the ecological significance of interspecies associations and the potential role they play in shaping marine food webs and helping predators adapt in a changing ocean. The researchers say further investigation is needed to understand how widespread and consistent such co-operative behaviours may be. 

“By combining aerial and underwater information, we’re uncovering a hidden layer of coordination between species,” said Dr. Fortune. ”It’s a striking example of how new technology is helping us rethink the relationship between top predators in the ocean.” 

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Coral Reef Survival: Depth, Marine Protected Areas, and Seascape Structure Are Key

Blasted coral. Credit: Jenny Selgrath/Project Seahorse

VANCOUVER / PHILIPPINES — Living corals are more likely to survive and thrive when found in deeper water, within Marine Protected Areas (MPAs), or in compact reef patches, according to a new study by UBC researchers published in People and Nature.

Coral reefs are among the most diverse and valuable ecosystems on Earth. Living corals create shelter for hundreds of marine species, like an apartment building underwater. When corals die, this shelter is lost, leading to sharp declines in fish, invertebrates and biodiversity. Worryingly, climate impacts, overfishing, and untreated sewage pollution have taken a serious toll on these seascapes.

This newly published study focused on Danajon Bank in the Philippines, one of only seven double barrier reefs in the world. This remarkable structure, 135 km long, supports livelihoods and food security through small-scale fishing. The region is in the Coral Triangle, which is the global center of marine biodiversity, and is of huge biological, social and economic importance.

The study authors used modelling to identify factors associated with living versus dead corals, using satellite maps, local knowledge, and long-term fishing records. Such multidisciplinary methods allowed them to disentangle the complex relationships between human impact and ecological resilience.

Reefs are damaged by fishing

Fishers in the Philippines. Credit: Jenny Selgrath/Project Seahorse

“We found that every one and a half years of fishing at a site reduced the probability of living coral by 3.2%,” said Dr. Jennifer Selgrath, lead author on the paper who was a PhD candidate at UBC’s Institute for the Oceans and Fisheries (IOF)’s Project Seahorse during the study, and is currently a research scientist with NOAA Channel Islands National Marine Sanctuary and the California Marine Sanctuary Foundation. “And fishing has long-lasting impacts. Areas that had been heavily fished 10 to 30 years ago still have lower coral today.”

“We were disappointed to find only about 30% of the reefs we studied were dominated by living coral, so it was useful to discover that both ecological context and human activities shaped coral distribution,” noted Dr. Amanda Vincent, senior author on the study, Professor in the IOF and Director of Project Seahorse. “We found that the way the seascape was arranged mattered most, with living corals more likely in deeper areas, marine protected areas, and compact reef patches.”

“Worryingly, destructive practices like blast fishing—using explosives to catch fish—have greatly reduced coral cover. However, we were initially surprised to find that a slightly higher probability of corals in areas with blast fishing near human population centers”, shared Selgrath. “We then learned that those areas are full of mushroom corals. These free-living corals do not provide much shelter for other marine life, but they seem to be adapted to the unstable habitats created by blast fishing.”

Unlike most corals, mushroom corals can move to survive in unstable conditions, which helps explain why they persist even in heavily disturbed, blast-fished areas.

Depth, marine protected areas and seascape features help reduce damage

“Our finding supports evidence that depth helps corals persist under multiple stressors, including hurricanes, marine heatwaves, and fishing. We identified an 8% increase in probability of living corals per 2.25 m of depth. We also found a positive relationship between small community-managed marine protected areas (MPAs) and the presence of living coral. Corals were 18% more likely to be found inside MPAs than outside them,” said Selgrath.

Fishers in the Philippines. Credit: Jenny Selgrath/Project Seahorse

Fishers in the Philippines. Credit: Jenny Selgrath/Project Seahorse

“Communities in the Danajon Bank and our partners with ZSL Philippines have worked very hard to set up a network of MPAs. It is inspiring to see that these MPAs are working to protect corals and our oceans.”

Vincent concurs. “Protected areas are working, but they face an increasing array of regional and global stressors, including marine heat waves and disease. Climate stressors should be included in future MPA planning for oceans, and for the people who depend upon them.”

“Beneficial landscape characteristics like depth and patch compactness can be incorporated into marine spatial planning, restoration, and monitoring,” added Vincent. “For example, new MPAs could be placed in sites with deeper waters and compact coral patches, while restoration could focus on expanding existing coral areas.”

“We show that conservation outcomes depend on both reducing harmful stressors and strengthening the natural features that help corals survive,” shared Selgrath. “Key priorities include reducing spatial overlap of destructive activities, protecting reef configurations that support living corals, and addressing stressors that have delayed impacts such as legacy fishing.”

The study, “The influence of multiple stressors on the spatial distribution of corals” was published in People and Nature.

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Opportunities exist for Canada’s mariculture industry despite climate change, UBC study says

Climate change presents both risks and opportunities for Canada’s marine aquaculture (mariculture) industry. A new study from the University of British Columbia shows that while climate change will impact mariculture, for both mollusc and finfish species, on Canada’s Pacific and Atlantic coasts, strategic changes in production, policy, infrastructure, and spatial planning could turn many of these challenges into opportunities.

Canada’s mariculture industry has grown substantially in recent years, with production increasing from approximately 92,500 tonnes in 1998 to 159,800 tonnes in 2022. In 2022, the industry contributed around $1.2 billion to the Canadian economy and employed 3,900 full-time individuals, many in remote coastal regions where traditional industries, such as fishing and forestry, are in decline. Approximately half of Canada’s mariculture production comes from British Columbia, primarily along the province’s south coast. In Atlantic Canada, mariculture production is spread across the provinces; New Brunswick, leading with 17 per cent of national production, followed by Prince Edward Island (13 per cent), Newfoundland and Labrador (10 per cent), Nova Scotia (5 per cent), and Quebec (1 per cent).

The study analysed the future of Canada’s mariculture sector under contrasting climate and socio-economic scenarios. Two climate-related scenarios and two production approaches were used to project the regional impacts of climate change, consequences on thirteen key marine species along Canada’s Atlantic and Pacific coasts, as well as socio-economic effects.

Description of climate-socioeconomic and production scenarios used to model mariculture futures in Canada.

Description of climate-socioeconomic and production scenarios used to model mariculture futures in Canada.

“The various scenarios and approaches gave us a broader understanding of how climate change will affect mariculture on both coasts,” said Dr. Muhammed Oyinlola, lead author on the study and a postdoctoral fellow in the Institute for the Oceans and Fisheries. “We see substantial regional contrasts, with the Atlantic region showing modest gains under a low-emission climate scenario, but declines under a high-emission scenario because of climate stress and habitat loss. In contrast, Pacific Canada shows strong growth potential under both scenarios.”

“The potential opportunities for production growth in Pacific Canada, particularly in its central and northern areas, have a lot to do with species that are being farmed,” added Dr. William Cheung, senior author of the study and professor and Director of the Institute for the Oceans and Fisheries. “In Pacific Canada, aquaculture focuses on farming finfish salmonids such as climate-resilient Coho salmon, Chinook salmon, and steelhead trout. Our projections show that while the South coast is likely to experience declines as conditions become less suitable, and the Central coast may experience some mid-century decline, it is expected to rebound there up to 32% by the end of the century. The North coast shows positive gains under both scenarios.”

Atlantic Canada’s mariculture sector is more focused on mollusc farming (blue mussels, bay scallops, eastern and European flat oysters, and hard clams), with some finfish species like Atlantic salmon, cod, and halibut. “Our results show that in Atlantic Canada, farmed finfish, and shellfish species can benefit from future climate scenarios, but with strong regional variation,” said Oyinlola. “On the Newfoundland and Labrador Shelves, marine area that is potentially suitable for mariculture is projected to increase under both scenarios (up 28 per cent in the 2050s and 36 per cent by the 2100s under the low impact scenario, and increases of 33 per cent in the 2050s and 80 per cent by the 2100s under the hard scenario). The Gulf of St. Lawrence (17 per cent and 23 per cent respectively) and the Scotian Shelf (2 per cent in the 2050s and 8 per cent by the 2100s) show modest increases under the low-emission climate change scenario, but both regions are projected to decline under the high-emission scenarios by 8 per cent and 19 per cent for the Scotian Shelf and 28 and 55 per cent for the Gulf of St. Lawrence at mid and end-century, respectively, due to declining habitat suitability and the sensitivity of key species.”

Projected percentage change in mariculture production (tonnes), farm-gate price, and employment for Canada’s Pacific and Atlantic

Projected percentage change in mariculture production (tonnes), farm-gate price, and employment for Canada’s Pacific and Atlantic coasts by the 2050s and 2100s.

Panels (a) and (b) show results across three production scenarios: Baseline, Socio-Economic Drivers, and Static Spatial Footprint. Bars represent mean change; error bars indicate standard deviation. Blue represents production tonnes, pink represents farm-gate price, and yellow represents employment.

Climate, however, is only part of the story. “Whether the potential can be realized sustainably and the associated ecological, social and economic risks from expansion of mariculture depends on regional policies, infrastructure, and spatial planning that reconcile mariculture expansion with conservation, Indigenous uses, and other priorities,” said Cheung. “Rising farm-gate prices – price for aquaculture products at the point of first sales – may benefit producers, but the uneven spatial distribution of suitable marine areas on both coasts and the projected changes in employment, pose serious challenges. We see consistent job losses in Atlantic Canada under many scenarios, with only limited or uncertain gains in the Pacific.”

“Technological and management innovations, such as selective breeding, diversified farming systems, and, in some cases, closed-containment or integrated multi-trophic aquaculture, can enhance resilience,” said Oyinlola. “Ultimately, the sustainability of Canada’s mariculture will depend on how well we respond to regional climate change and harness emerging opportunities through innovation, inclusive food policies, and investments in resilient infrastructure.”

“Opportunities and challenges for Canada’s mariculture under climate change: a regional and sectoral outlook” was published in FACETS.

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Marine heatwaves quietly rewire ocean food webs

Marine heatwaves often make news when corals bleach or fish wash up dead. A new global study led by researchers at UBC and L’Institut Agro shows that bursts of extreme ocean heat are also reshaping the entire structure and function of marine food webs, with consequences that can last years after the water cools.

These heatwaves, defined as at least five days of unusually warm sea surface temperatures above a locally determined extreme threshold, have already become more frequent, longer, and more intense over the past century, with well-known examples like the northeast Pacific “Blob”, recent Mediterranean heatwaves, and repeated events in the Tasman Sea.

“Marine heatwaves are strongly and persistently reshaping marine food webs,” said Dr. William Cheung, professor in the Institute for the Oceans and Fisheries (IOF), and co-author of the study. “Even though these events can last only weeks to months, their effects on the ecosystem can linger for years, especially for large predators that recover slowly. It really highlighted that extreme events, not just gradual warming, can drive long term ecological change.”

Dr. Vianney Guibourd de Luzinais, first author, and a Ph.D. student in the IOF and L’Institut Agro at the time this study was prepared, was struck by how deeply these short, intense events reverberate through marine ecosystems. “What surprised me most was how profoundly marine heatwaves alter the structure and functioning of ecosystems,” he said. “Although these events are short-lived but extremely intense, their effects ripple through the entire food chain and persist long after the heatwave has ended, leaving many ecosystems too little time to fully recover before being hit again, resulting in long-term ecological modifications.”

Published in the journal Biogeosciences, the study uses a trophodynamic ecosystem model, called EcoTroph-Dyn, to ask a key question: what extra damage do marine heatwaves cause on top of the slower, background warming of the ocean?

The global picture that emerged was stark. In a world with only gradual warming, total consumer biomass from trophic levels were projected to decline by about 0.07 percent per year between 1998 and 2021. When marine heatwaves were included, that average decline nearly doubled to about 0.12 percent per year. Standard projections based only on mean temperature trends would underestimate how much biomass is being lost from marine ecosystems.

Declines would be most pronounced in tropical systems, which support many of the world’s most productive fisheries. High trophic levels, representing larger predators, lost a greater fraction of their biomass than lower levels and remained depressed for longer. The model also showed that including heatwave driven mortality led to an additional biomass loss of roughly 3 percent. In several places, such as the California current and Alaska coastal waters, total biomass has still not returned to pre-Blob levels by 2021.

The study also shows that heatwaves do more than simply reduce biomass. They change how energy moves through the food web. During events like the Blob, flow kinetics, the speed at which biomass moves from prey to predators, increased, while transfer efficiency, the fraction of energy passed between trophic levels, decreased. Warmer water raises metabolic costs, so organisms burn more energy just to maintain basic functions, leaving less to support growth and reproduction and less to pass up to larger predators. Over time, that favours communities of smaller, faster growing species and erodes the biomass of slow growing top predators, including commercially important fish such as tuna and salmon.

“Our use of the model was deliberately simple and did not resolve individual species or seasonal life cycles,” said Guibourd de Luzinais. “It still captured broad patterns that match observations and other ecosystem models, suggesting that in many regions, especially in the tropics, marine heatwaves are arriving more often than ecosystems can fully recover, ratcheting down biomass at higher trophic levels over time.”

For fisheries and conservation planning, the message is clear. “Management strategies that only account for gradual ocean warming risk underestimating future pressures on fish stocks and ecosystem services,” said Cheung. “As extreme events such as marine heatwaves continue to intensify, they will drive the trajectory of marine ecosystems, and we will need to develop adaptation strategies that recognise the growing role of climate extremes in shaping life in the sea.”

Marine heatwaves deeply alter marine food web structure and function was published in Biogeosciences.

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Dr. William Cheung inducted as a Fellow of the Royal Society of Canada

On Friday, November 14, 2025, Dr. William Cheung, professor and Director of the Institute for the Oceans and Fisheries, was inducted into the 2025 cohort of Royal Society of Canada (RSC) Fellows.

Dr William Cheung inducted into the 2025 cohort of Royal Society of Canada (RSC) Fellows

Why Dr William Cheung was selected as a RSC Fellow

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Diet alone doesn’t explain divergent health of California Sea Lions in US and Mexico

Sea lion - © Ana Pozas

Sea lion – © Ana Pozas

When scientists compared what California sea lions eat in the Channel Islands (U.S.) and the Gulf of California (Mexico), they expected to find a clear explanation for why populations were booming in California but shrinking in Mexico. Instead, they found something more complicated.

The study found that what sea lions eat may matter less than where they live. Despite large regional differences in population trends, the study found that the overall energy value of sea lion diets in the Gulf of California and the Channel Islands was nearly identical.

“What surprised us most was that, even though sea lion populations in the Gulf of California are declining while those in the Channel Islands are thriving, their overall diet quality was similar,” said Ana Lucía Pozas-Franco, a master’s graduate at UBC’s Institute for the Oceans and Fisheries. “This highlighted how this region is a patchwork of different environments – environmental heterogeneity, rather than diet quality alone, influences sea lion population trends in Mexico.”

Sea lions on rocks © Ana Pozas

Sea lions on rocks © Ana Pozas

Pozas-Franco says this variability underscores how much local conditions matter. “Because California sea lions in Mexico are under special protection due to overall population declines, management plans should focus on understanding the unique conditions of each colony and the factors influencing population dynamics regionally.”

Dr. Andrew Trites, professor in the Institute for the Fisheries and Oceans, Director of UBC’s Marine Mammal Research Unit, and one of the study’s coauthors, said the findings challenge common assumptions. “It’s tempting to assume that diet quality directly drives population size,” he said. “But these results show that the same prey energy can yield very different outcomes depending on local oceanography, prey availability, and human pressures. Each colony lives in its own ecological neighbourhood.”

California sea lions range from British Columbia to Mexico’s Gulf of California, but their fates have diverged sharply over the past forty years. In the U.S., populations at the Channel Islands have increased by several percent each year since the 1980s, while most colonies in Mexico have declined at a similar rate. To understand why, the researchers analyzed four decades of data on sea lion populations and diets, comparing what animals in each region were eating and how their numbers were changing over time.

Researchers measured two main aspects of “diet quality.” One was energy density, which captures how much energy each gram of prey provides. The other was diversity, measured using the Shannon Diversity Index and the number of main prey species making up a sea lion’s diet. On both counts, the two regions were surprisingly similar. Sea lions in the Channel Islands had diets averaging about 5.4 kilojoules per gram of wet weight, while those in the Gulf of California averaged 5.3. In other words, both populations were eating equally rich food. Yet the Gulf’s colonies were declining.

The composition of each diet, however, told a different story. Sea lions in the Channel Islands fed mainly on a small number of schooling fish and squid species such as anchovy, mackerel, and market squid. In contrast, those in the Gulf of California ate an impressive 88 different main prey species, dominated by benthic species and schooling fish. The wider menu didn’t make them better off. The team found no simple link between how diverse or energy-rich a diet was and whether a colony was growing or shrinking.

During the 2014–2016 Pacific heatwave known as “The Blob,” sea surface temperatures rose across the region and disrupted prey availability. In the Gulf of California, sea lions shifted toward eating more benthic fish and fewer schooling fish and squid, which caused a measurable drop in the energy density of their diet. Yet even this shift had mixed effects. Some colonies experienced temporary declines, while others appeared unaffected.

The Gulf of California, Trites added, is a particularly complex neighborhood. “It is a mosaic of subregions shaped by different currents, temperatures, and prey communities. In the southern Gulf, around places like Los Islotes, sea lion numbers have remained stable or even increased. Farther north, colonies have struggled as warming and changing prey patterns made their foraging grounds less reliable.”

Pozas with sea lion © Ana Pozas

Pozas with sea lion © Ana Pozas

For conservationists, this means there is no single problem with the sea lion populations in the Gulf of California. Protecting the species requires understanding how each rookery interacts with its environment, how prey species change, how females alter their foraging trips, and how local fishing activity or pollution might tip the balance. The authors argue that better long-term monitoring is needed to track these shifts and to distinguish between natural fluctuations and human-driven change.

Instead of asking whether sea lions are eating the right food, this study asked how a changing ocean is shaping the food that’s available, and how adaptable sea lions can be in response. The answer, it seems, depends on where they happen to live.

“Environmental heterogeneity plays a bigger role than diet quality in driving divergent California sea lion population trends,” appeared in PLOS One.

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West Coast mammal-eating killer whales are two distinct communities that rarely mix

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