Seafood Lovers Beware: Could Trump Policy Make Shrimp Smaller?

Arthropod raised in warmer lab conditions matured earlier — and smaller, which has vast implications for the warming world. Wouldn’t you know, butterflies aren’t affected.

FILE - In this July 2007, file photo, a scientist holds a lobster underwater on Friendship Long Island, Maine. Officials with Sweden told The Associated Press in January 2017 that their country is working on a new proposal about how to deal with American lobsters that turned up in Swedish waters. Sweden had asked the European Union in March 2016 to bar imports of live American lobsters into the 28-nation bloc after 32 American lobsters were found in Swedish waters. (AP Photo/Robert F. Bukaty, File)
A scientist holds a lobster underwater on Friendship Long Island, Maine. Robert F. Bukaty/AP

U.S. President Donald Trump is diverting federal funds from climate-change research to job creation. Workers in Trump’s America may want to avoid breeding lobsters and shrimp, or farming, going by a new study showing that arthropod size depends on the temperature of their surroundings. The warmer the environment, the smaller the arthropod, from bees to shrimp to millipedes.

In cold-blooded animals, including arthropods, body temperature depends on the ambient temperature. So does size, at least in the laboratory. When arthropods, such as insects, crustaceans and other creatures with external skeletons, are grown in warmer conditions, they usually develop more quickly, and are smaller when mature.

“This biological phenomenon occurs in over 83 per cent of cold-blooded species,” wrote biologists Curtis R. Horne and Andrew G. Hirst, from Queen Mary University of London, and David Atkinson, from the University of Liverpool, in an article that was published on Wednesday in Proceedings of the Royal Society B: Biological Sciences.

So in a warmer world with warmer oceans, lobsters, shrimp and other crustaceans are likely to be smaller.

As always in biology, the number of parameters that can affect any given characteristic, including the final size of adult shrimp or anything else, is vast. Other conditions that affect arthropod body size include the amount of oxygen in the water. But in the largest-ever analysis of data on seasonal arthropod body size variation around the world, the researchers say they found a statistically significant match to temperature, and it’s worse in the water than on dry land.

“Aquatic species show approximately 2.5-fold greater reduction in size per degree-Celsius of warming than terrestrial species, supporting the hypothesis that greater oxygen limitation in water than in air forces aquatic species to exhibit greater plasticity in body size with temperature,” they write.

Clearly, if arthropods shrink, it will have an ecological impact, which in turn will have an economic impact. “Arthropods are of huge economic and ecological value to humans,” said Horne. “For example, they include important species of pollinators, as well as zooplankton species, the most abundant animals in our ocean that form the basis of the food chain for commercially important fish species. It is in our interest to understand how these species will respond to warming.”

It bears qualifying that each species reacts to temperature in its own way: Some are more affected than others. “In particular, aquatic species including important species of zooplankton, reduce their size much more with seasonal warming compared to species on land such as aphids and butterflies,” write the scientists.

On Tuesday, flanked by coal miners, Trump signed an executive order dismantling the Obama administration’s Clean Power Plan. According to an article posted on the GQ website on Tuesday, the move demonstrates the new administration’s “shockingly feeble grasp of basic economics concepts,” according to GQ magazine and, its title suggests “will put us all underwater.” Well, if that water is warmer, arthropods will be smaller, the pollination of our food crops could be compromised and our dinners aside, how it will affect global environment is anybody’s guess.