Overfishing of Atlantic Cod Likely Did Not Cause Genetic Changes: Pinsky et al. paper out in PNAS

This article was adapted from Todd Bates’ press release.

Atlantic cod
Bottom-dwelling fish such as Atlantic cod are often found near structures such as
shipwrecks. Photo: NOAA

Overfishing likely did not cause the Atlantic cod, an iconic species, to evolve genetically and mature earlier, according to a study led by Drs. Malin Pinsky and Bastiaan Star.

“Evolution has been used in part as an excuse for why cod and other species have not recovered from overfishing,” said Malin. “Our findings suggest instead that more attention to reducing fishing and addressing other environmental changes, including climate change, will be important for allowing recovery. We can’t use evolution as a scapegoat for avoiding the hard work that would allow cod to recover.”

The study, which focuses on Atlantic cod (Gadus morhua) off Newfoundland in Canada and off Norway, appears in the journal Proceedings of the National Academy of Sciences.

Atlantic cod range
Atlantic cod habitat includes both sides of the north Atlantic Ocean and beyond. Image: NOAA

Many debates over the last few decades have centered on whether cod have evolved in response to fisheries, a phenomenon known as fisheries-induced evolution. Cod now mature at a much earlier age, for example. The concern has been that if the fish have evolved, they may not be able to recover even if fishing is reduced, according to Pinsky.

Cod populations with late-maturing individuals can produce more offspring and more effectively avoid predators, he said. They are also better protected against climate variability.

Both theory and experiments suggest that fishing can lead to an earlier maturation age. But prior to the new study, no one had tried to sequence whole genomes from before intensive fishing to determine whether evolution had occurred. So, this team sequenced cod earbones and scales from 1907 in Norway, 1940 in Canada and modern cod from the same populations. The northern Canadian population of cod collapsed from overfishing in the early 1990s, while the northeast Arctic population near Norway faced high fishing rates but smaller declines.

The team found no major losses in genetic diversity and no major changes that suggested intensive fishing induced evolution, suggesting that we focus on managing for more direct threats (e.g., overfishing, environmental change) than for evolution.

This study prompts future investigations to see if other species, especially those with shorter lifespans (in contrast to cod), do or don’t show signs of evolution.

Scientists at the University of Oslo, Fisheries and Oceans Canada, Institute of Marine Research (Norway), University of Basel and University of Zurich contributed to the study.

Read additional coverage by Science Magazine here!

Read the original press release here!

Deadly White-Nose Syndrome Changed Genes in Surviving Bats: Gignoux-Wolfsohn et al. paper out in Molecular Ecology

A little brown bat that survived white-nose syndrome. Photo: Sarah Gignoux-Wolfsohn

This post is adapted from Todd Bates‘ article in Rutgers Today.

Former Pinsky Lab Post-doc, Dr. Sarah Gignoux-Wolfsohn led a study in Molecular Ecology which uncovered the genetic differences between bats killed by white-nose syndrome and bats that survived. She was supported by a team of co-authors from Rutgers (Dr. Malin Pinsky, Dr. Kathleen Kerwin, and Dr. Brooke Maslo), the NY Department of Environmental Conservation, the NJ Department of Enviornmental Protection, the Vermont Fish and Wildlife Department, and the University of Tennessee. Their results suggest that survivors pass on traits for resistance to the fungal disease causing rapid evolution in exposed bat populations.

White-nose syndrome has killed millions of bats in North America since 2006, following its introduction from Europe. The syndrome, caused by the fungal pathogen Pseudogymnoascus destructans, is arguably the most catastrophic wildlife disease in history. It has led to unprecedented declines in many North American bat species, including the little brown bat (Myotis lucifugus).

“Our finding that little brown bat populations have evolved, which could be why they survived, has large implications for management of bat populations going forward,” said lead author Sarah Gignoux-Wolfsohn, a former postdoctoral associate at Rutgers University–New Brunswick now at the Smithsonian Environmental Research Center in Maryland. “Management decisions, such as whether to treat for white-nose syndrome or protect populations from other detrimental factors, can be informed by knowing which bats are genetically resistant to the disease.”

“The deployment of vaccines or treatments for the fungus may be most needed in populations with few disease-resistant individuals,” said Gignoux-Wolfsohn, who led the study – published in the journal Molecular Ecology – while at Rutgers. “Our study also has implications for other diseases that cause mass mortality. While rapid evolution in response to these diseases is often difficult to detect, our study suggests it may be more common than previously thought.”

The team sequenced bat genomes from three hibernating colonies in abandoned mines in New York, New Jersey and Vermont to determine whether little brown bats evolved as a result of the disease. They compared the genomes of bats killed by white-nose syndrome to survivors in recovering populations to identify genetic differences that may be responsible for survival.

The bats’ evolution appears to have particularly affected genes associated with weight gain before hibernation and behavior during hibernation. Rapid evolution may have allowed the remaining bats to keep hibernating and survive infection that killed off millions of other bats.

“Evolution is often thought of as a process that happened long ago,” Gignoux-Wolfsohn said. “We have found that it has also been happening right in our backyards and barns over the last decade.”

This group is now conducting a similar study in Indiana bats (Myotis sodalis). While also affected by white-nose syndrome, this species has experienced lesser declines than little brown bats.

Read the article in Molecular Ecology.

Read additional news coverage in Rutgers Today and Yahoo! News.

Thermal affinities and temperature gradients explain how warming changes ocean community composition: Burrows et al. 2019, Nature Climate Change

Figure 1, c-f (Burrows et al. 2019) Thermal characteristics in simulated pools of species varying in thermal diversity (high: c and d; low: e and f) and species’ thermal ranges [STR] (narrow: c and e; wide: d and f), showing subsets forming communities at a mean annual sea temperature of 15 °C.

A new paper published in Nature Climate Change by Dr. Michael Burrows et al., with contributions from Dr. Ryan Batt (former Pinsky Lab postdoc) and Dr. Malin Pinsky, used 29 years of fish and plankton survey data to assess how warming is changing marine communities’ composition and structure. They found that “warm-water species are rapidly increasing and cold-water species are decreasing” as ocean waters warm. Informed by species’ incidence, and changes in sea surface temperature (SST), the team created measures of species’ thermal affinities, community composition, and other summary metrics. They used these to measure community-level change in thermal affinity and composition.

Regions with relatively stable temperatures (e.g. the Northeast Pacific and Gulf of Mexico) showed little change in structure, while areas that warmed (e.g. the North Atlantic) shifted strongly towards warm-water species dominance. They also found that communities whose species pools had diverse thermal affinities and a narrower range of thermal tolerance showed greater sensitivity to change.

Next, they found that communities in regions with strong temperature depth gradients changed less than expected. In these regions, rather than moving horizontally through the water, species can instead move deeper to maintain their preferred temperature.

They concluded that this evidence strongly supports temperature as a fundamental driver of change in marine systems, and that metrics based on species’ thermal affinities are useful tools to predict and provide prognoses for community dominance shifts.

Check out press coverage of the article below:

Changes in both size and distribution of fish stocks on the US West Coast drive variation in availability to fisheries: Selden et al. article in ICES JoMS

Block seine fishing. Image courtesy of WDFW.
Commercial fishing boat hauling up a block-seine trawl. Image from Washington Department of Fish and Wildlife.

Changes in the total catch of a species do not always correspond to changes in total biomass or changes in the species’ distribution alone. This discrepancy drove Dr. Rebecca Selden, former Pinsky lab post-doc and current Assistant Professor at Wesleyan College, and colleagues to seek a greater understanding of the forces driving both fish stock availability and catch at US West Coast ports in their recently published article.

The team first sought to couple changes in a species’ biomass with the species’ distribution to explain the heterogeneity in stock availability experienced by fisheries across different latitudes. They measured the change in distribution and biomass of five commercial target species (dover sole, thornyheads, sablefish, lingcod, and petrale sole), and found that the timing and magnitude of stock declines and recoveries are not experienced uniformly along the coast when they coincide with shifts in species distributions.

Second, they integrated information on distances travelled by fishers with estimates of availability along the coast to generate port-specific indices of availability. They found that additional factors, like greater vessel mobility and larger areal extent of fish habitat, affect availability, and may work to counteract or augment the effects of changing fish biomass and distribution.

Lastly, they found that higher stock availability was not consistently associated with higher catch per ticket. Because fish landings were not consistently related to stock availability, Selden et al. suggest that social, economic, and regulatory factors likely constrain or facilitate the capacity for fishers to adapt to changes in fish availability.

Conservation planning for species evolving with climate change: new article in Nature Climate Change

A coral reef off Cuatros Islas in the Philippines.
Photo: Michelle Stuart/Rutgers University-New Brunswick

Drs. Timothy Walsworth, Daniel Schindler, Madhavi Colton, Michael Webster,  Stephen Palumbi, Peter Mumby, Timothy Essington, and Malin Pinsky authored a paper exploring the efficacy of various management strategies to protect species in the face of warming ocean temperatures. While previous research addressed where to establish protected areas, nearly all studies overlooked the fact that most species can also evolve in response to climate change, despite growing evidence that rapid evolutionary response can occur. The paper focused in particular on corals.

The team evaluated a range of potential conservation strategies, including protecting: 1) the hottest 2) the coldest and 3) both the hottest and coldest sites at the time of site selection; sites with the 4) highest and 5) lowest abundance at the time of site selection; 6) sites that are evenly spaced across the entire network, and 7) randomly selected sites about the networks. The researchers found that strategies conserving many different kinds of sites would work best (e.g. 6 and 7).

“Rather than conserving just the cold places with corals, we found that the best strategies will conserve a wide diversity of sites,” Malin explained. “Hot reefs are important sources of heat-tolerant corals, while cold sites and those in between are important future refuges and stepping stones for corals as the water heats up.”

Click to read the full article

Press coverage:

Climate Change Threatens Commercial Fishers From Maine to North Carolina – Rogers et al. article in Nature Climate Change

Lobster boats anchored off Cutler, Maine.
Photo: Malin Pinsky/Rutgers University-New Brunswick

Drs. Lauren Rogers, Robert Griffin, Talia Young, Emma Fuller, Kevin St. Martin, and Malin Pinsky collaborated on a paper which seeks to understand how climate change will likely affect the fishing opportunities for 85 communities in New England and the Mid-Atlantic. The team integrated climatic, ecological and socio-economic data to identify where strategies for adapting to the ecological impacts of climate change will be most needed. They used 13 global climate models to project how ocean temperatures are likely to change, then examined ocean temperatures and types of bottom habitat to determine where important commercial fisheries species are likely to move. They also looked at whether the species caught by fishing communities are likely to become more or less abundant in the ocean regions where they typically fish.

Read more about the paper from the news outlets below:

Climate Change Hits Sea Creatures Hardest: Malin et al.’s new paper in Nature [edit: and the cover!]

Pinsky et al. 2019 makes the cover of Nature!

Malin and coauthors, Drs. Anna Eikeset, Doug McCauley, Jonathan Payne, and Jennifer Sunday, published a paper on April 24th, 2019 on the vulnerability of marine versus terrestrial ectotherms. While the vulnerability of marine and terrestrial fauna have each been studied in isolation, a direct comparison of marine and terrestrial organisms physiological sensitivity to warming has yet to occur.

The team used species’ thermal safety margin (the difference between the hottest temperature that an organism can safely tolerate, and its hottest hourly body temperature when in the coolest part of their environment) as a tool to directly compare ocean and land dwelling species. This metric approximates the amount of additional warming a species can tolerate. They calculated this metric for 88 marine and 299 terrestrial species, and found that marine species are more likely to live close to their upper thermal limit than terrestrial species. Terrestrial species also have greater access to thermal refugia (cooler places found within their habitat), such as shaded or subterranean areas. Both of these factors make marine organisms more sensitive to warming than their terrestrial counterparts.

Click here to read the full paper (free access here), and here to read the Rutgers press release.

Key figure from Pinsky et al. 2019

Additional Press Coverage:

Fisheries’ decline due to ocean warming published in Science

Chris Free, Malin, Olaf Jensen, and co-authors recently published an article on fisheries decline in Science. The study found that climate change has already taken a toll on many of the world’s fisheries, and overfishing has magnified the problem. Ocean warming led to an estimated 4.1 percent drop in sustainable catches, on average, for many species of fish and shellfish from 1930 to 2010. In five regions of the world, including the East China Sea and North Sea, the estimated decline was 15 percent to 35 percent, the study says.

The team combined global data on fisheries with ocean temperature maps to estimate temperature-driven changes in the the maximum sustainable yield from 1930 to 2010. Their analysis covered about one third of the reported global catch, and losing species outweighed the winners as the oceans warmed.

Haddock in the North Sea are among the climate change “losers” as a result of warming ocean temperatures. Photo: NEFSC/NOAA Scientists at Rutgers–New Brunswick and the National Oceanic and Atmospheric Administration studied the impact of ocean warming on 235 populations of 124 species in 38 ecological regions around the world. Species included fish, crustaceans such as shrimp, and mollusks such as sea scallops. High Res

Press coverage:

Ocean currents shape the geography of life in the Coral Triangle

Coral dispersal in an oceanographic model for the western tropical Pacific

In a new paper published online today in Progress in Oceanography, Diane Thompson and collaborators (including Malin) show how ocean currents transport coral larvae throughout the western Tropical Pacific, and how the barriers posed by these currents have helped shape where species are found.

Link for free access until July 27, 2018 is here.

Thompson, D., J. Kleypas, F. Castruccio, E. Curchitser, M. L. Pinsky, B. Jönsson, and J. Watson (2018). Variability in oceanographic barriers to coral larval dispersal: do currents shape biodiversity? Progress in Oceanography 165: 110-122 doi: 10.1016/j.pocean.2018.05.007