Climate Change Could Spell Seafood Shortage

Climate Change Could Spell Seafood Shortage

By Margaret Blagbrough, Environmental Science, 2017

Imagine — a future in which seafood restaurants in the most popular beach resort towns are no longer in business. Why? Thank climate change. According to a recent study by scientists at the National Oceanic and Atmospheric Administration, over 50 percent of fish and invertebrate species that live in the Atlantic Continental Shelf are either highly vulnerable or very highly vulnerable to climate change. Vulnerability refers to the increased possibility that warming will reduce species’ productivity as well as abundance. High vulnerability, along with already dropping numbers of species from overfishing, could prove to be disastrous for restaurant owners, seafood lovers, fishermen, and the marine ecosystem itself.

The vulnerability assessments performed in this study combined information on the exposure of a species to a climate change stressor as well as how sensitive that species will be to the stressor. The assessment included 82 fish and invertebrate species in the Northeast U.S. Shelf, stretching from North Carolina to the Gulf of Maine. Using climate projections from 2005–2055, the team picked various climate exposure factors that are known to have effects on fish populations and productivity.

These included ocean surface temperature, air temperature, mean precipitation, ocean pH (as a proxy for ocean acidification), and sea level rise. Biological attributes were also used to represent traits that can indicate how species will respond to climate change. For example, if a species has a low adult mobility, if their habitat becomes inhabitable due to warm temperatures, they will have nowhere to go, so the species overall will respond negatively to climate change. Other biological factors include: stock size, population growth rate, prey and habitat specificity, and sensitivity to temperature.

For both climate exposure and sensitivity, species could be rated as low, moderate, high, or very high. The scores for each were combined into an overall vulnerability rating. For the overall rating, 50% of species were either very high or highly susceptible to a change in abundance due to climate change in the near future.

Specifically, many species that tend to show up on our dinner plates made the list as highly vulnerable. Take for example, the bay scallop. A popular seafood choice for many, the bay scallop is ranked as very highly vulnerable. Scallops, and bivalves as a whole, will be severely impacted by ocean acidification. Sea level rise in particular can decimate bay scallop populations, because they spend their time both in coastal and marine habitats. Because of the fact that scallops are essentially immobile, they are even more at risk if their current habitats are destroyed. Atlantic sea scallops are also extremely vulnerable, because ocean acidification hurts them.

Another fish that most of us enjoy, Atlantic Cod, has already been in trouble for some time now. This species has been overfished since at least the 1500s and continues through today. This can be attributed to its popularity as a white fish and its use in popular dishes such as fish and chips. This study confirms the grim future for this species. It is highly sensitive to ocean acidification as well as sea surface temperature.

Besides the concern for those who like to eat seafood, the commercial and recreational fisheries in the Northeast Shelf are valued at $16.4 billion. The fisheries support countless jobs, from fishery managers to fishermen. Recreational fishing also supports jobs for charter boat captains. In Cape Cod, charter boats take many families out to sea to catch large striped bass. These striped bass are rated as very highly vulnerable to climate change, specifically threatened by ocean acidification, changes in air temperature, and changes in sea surface temperature. So, not only will families lose this bonding experience, but boat captains will also lose their livelihoods should climate change harm striped bass populations. Beyond this, there are many countries that rely on fish as their primary source of protein. Should these species disappear, food scarcity could become a widespread problem. Removal of top predators from the food chain can lead to increased populations of smaller fish and other organisms further down on the food chain, disturbing the delicate balance that is the marine ecosystem.

So, what can be done to prevent further damage to sensitive fish species? Seafood lovers can find alternatives to threatened species, such as eating haddock, which is ranked as having a low vulnerability to climate change, instead of cod. We can continue to vote for leaders who will do their part to slow down climate change in the United States. By doing our part, we can prevent a loss of these precious species and prevent a collapse of a valuable ecosystem.