What happens to marine life after hurricanes?


The 2017 Atlantic hurricane season has produced extreme impacts on people in the Caribbean and United States and all over the globe and have been destructive to many human settlements. There have been personal, economical and even political impacts that have emerged from this season's powerful storms.

In addition to impacts on dry land, hurricanes also have the potential to impact life in the water.

While it is too early to tell the impacts on marine life from the 2017 Atlantic hurricane season, there have been notable changes in salinity and temperature, according to Zachary Darnell, assistant professor in the division of coastal sciences at the University of Southern Mississippi.

“You see big changes in those after you see a storm that dumps inches of rain in a given area,” Darnell said.

One of the most significant impacts on marine life is from the massive increase of fresh water in a system, which will dramatically lower the salinity in an estuary.

“Marine animals have either specific salinity ranges that they can tolerate, or have a preference for certain salinities,” Darnell said. “So if the water is too fresh they either won’t survive or will move to a saltier area.”

Sea Turtle

A sea turtle named Picasso carries the ashes of Tony Amos, 80, a renowned oceanographer, on it's back as it is released back into the Gulf of Mexico following a memorial service, Saturday, Sept. 30, 2017, in Port Aransas, Texas. Amos died of complications from prostate cancer on Sept. 4, mere days after Harvey roared ashore as a fearsome hurricane. (AP Photo/Eric Gay)


Due to those changes, there is a shift in distribution of animals from the estuaries to an offshore area. Marine life that are unable to move see an increased mortality rate due to change in salinity.

Freshwater brings sediment from runoff and erosion along with it. Marine life like oysters, barnacles and plants that are unable to move will get buried in sediment.

Sea turtles see direct impacts during hurricanes as they build their nests on beaches. Incubating eggs can be directly hit by the storm, resulting in displacement and mortality.

According to experts at NOAA Fisheries, during and after hurricanes it is possible for marine mammals to enter waterways where they are not typically found. This displacement occurs as a result of storm surge and increased water levels associated with hurricanes.

Oftentimes animals will become stranded on land as a result of a hurricane. When encountering a stranded animal, NOAA Fisheries advise that the best course of action is to call a rescuer and stay with the animal until the rescuers arrive. A contact list for marine mammal rescuers around the country can be found on the NOAA website.

Those staying with the animal should keep its skin moist by splashing water over its body, but they should also be careful to minimize contact with it. The animal should not be pushed back into the water as the mammal could be sick or injured and pushing it back to sea could result in a worsening condition.

Hurricanes can be stressful to more than just animals that dwell in the sea. According to a Duke University-led study, hurricanes affect the mortality rate of migrating birds.

The study tracked the migration route of the sooty tern and the path of most Atlantic basin hurricanes, finding parallels between the two.

“The migration route overlaps both in space and in time with hurricanes and we found that there was a correlation between number of hurricanes and the mortality or deaths of the birds,” said Ryan Huang, a doctorate candidate studying ecology at Duke University.

According to Huang, sooty terns are more likely to die during migration when facing more hurricanes and stronger winds. Migration is a stressful process for the bird and the excess toll from a storm is likely to exhaust the bird, sometimes to the point of death.

Every year, over 80,000 sooty terns land at the Dry Tortugas National Park in the Florida Keys to breed from January to June. After leaving the islands, they migrate through the Caribbean and spend winter off the coast of Brazil. As the birds are usually in safe waters by August, hurricanes that occur earlier in the hurricane season pose more of a threat.

“Weak storms can also have a serious impact on birds -- its mainly about the timing, being in the wrong place at the wrong time.”

While exact impacts of the 2017 hurricane season won’t be known for a few more years, Huang predicts that this season will actually not have a large impact on the birds. Though there were frequent and intense storms, most storms occurred from late August and through September, while the largest concern for the birds is hurricanes that occur from June to August.

“As storms get potentially more common, the chances of these birds being at the wrong place at the wrong time increases,” Huang said. “The chances of stronger storms happening earlier in the season is likely to increase and that is a concern.”

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