Sea level rise threatens endangered species, even marine animals

Sea level rise is threatening the survival of species not only those that live their entire lives on dry land. Three of the five species considered most threatened on the US Endangered Species list are the Florida Key deer, loggerhead sea turtles and Hawaiian monk seals are all threatened by increases in sea level. It is surprising that the latter two are classified as marine animals living the majority of their lives in the ocean.

The Florida Key Deer 

A hundred miles south of Miami is a long strip of land populated by fairy-sized creatures. Big Pine Key, once renowned for its small round citrus the variety used to make key lime pies, is now known for its diminutive deer. The Key deer is a golden retriever-sized relative of the common white-tailed deer. Key deer are far more rare, found only on a few the low lying islands that make up the Florida Keys. Hunting and habitat loss brought about the deer’s decline until the last half century or so when the story became increasingly happy. The population has increased 33 fold, in the ensuing years. The success is attributable to the Endangered Species Act. A happy ending for the story of the Key deer, however, is far from assured due to a very real threat of sea level rise.

The Florida Keys are a string of low lying islands that lie south and west of Miami. In the area of Big Pine Key, the islands are made of ancient coral. It is estimated that three-quarters of the world’s key deer live on just two keys; both with elevations less than three feet above sea level. Although Key deer are reported to be strong swimmers, they are not adapted a marine species and are not adapted to survive if their terrestrial habitat were inundated by rising seas driven by climate change.

A sobering fact reported by The Center for Biological Diversity is how many species face  prospects similar to the Key deer. “Left unchecked, rising seas driven by climate change threaten 233 federally protected species in 23 coastal states.” Put another way, one in six of the nation’s threatened and endangered species are at risk from rising sea levels with the Key deer being one of five species considered the most threatened.

Hawaiian monk seal

Creatures, like the Key deer, dependent on dry land and fresh water are at extreme risk when the rise in ocean level threatens to inundate their home. What may come as unexpected is to read that of the 233 federal protected species in coastal states that the US Fish and Wildlife Service, National Marine Fisheries Service and others believe are threatened, of the top five, two spend the majority of their lives in the ocean. The Hawaiian monk seal and the loggerhead sea turtle are  considered marine animals because the majority of their lives are spent in the ocean. Their survival is in question because the beaches needed by the loggerhead to make nests and deposit their eggs and the monk seals to birth and rear their young are in danger.

The Hawaiian monk seal, like the Key deer, exists in a limited geographic area. The seals, as their name implies, is endemic to Hawaii. They are among the most endangered seal species in the world. The monk seal faces numerous threats including the availability of food resources, entanglement, and shark predation but the loss of suitable habitat for giving birth is significant and required for the survival of the species. The elevation of many of the low-lying atolls or islands in the northwest of the Hawaiian Archipelago used for birthing are less than 6.5 feet above sea level. Beach erosion from storm surge and sea level rise threaten the beaches that the seals come ashore to give birth. One of these breeding islands has already disappeared.

Loggerhead sea turtle

Loggerhead sea turtles are found worldwide and, like all sea turtles, they are protected under the Endangered Species Act. According to NOAA Fisheries, the loggerhead turtles that nest on beaches in the United States do so primarily along the Atlantic coasts of Florida, South Carolina, Georgia, and North Carolina and along the Florida and Alabama coasts in the Gulf of Mexico. Multiple factors threaten loggerheads including marine pollution, entanglement, and boat strikes. Most significant in terms of long-term species survival is the loss of nesting habitat. This habitat loss is caused by beach erosion, land development and sea level rise. A humbling example of the threat caused by sea level rise is taking place at the Archie Carr National Wildlife Refuge in Florida, where “42 percent of current loggerhead nesting beaches are expected to disappear with just 1.5 feet of sea-level rise.”

Are there life raft solutions?

Nathan Rott, correspondent for National Public Radio’s National Desk, reported that sea level has risen 8 inches in the past century. The rate is expected to increase with 3 to 4 feet more expected this century, possibly 6.5 by 2100. The rise is the result of the melting of ice caps as Earth’s warming accelerates. As sea level rises, more land along the coasts will become submerged, leading to the displacement of the creatures that lived there. Creatures, like the Key deer and the monk seal, have few or no other places to go. This situation presents a conundrum for the professionals charged with protecting the survival of the species.

Nikki Colangelo of the US Fish and Wildlife Service is a specialist in species conservation, mitigation, and recovery planning and implementation. Professionals like Colangelo must consider the costs, benefits, and efficacy of alternatives in the work to preserve species. The most practical alternatives under consideration appear to be moving a species to other areas within their geographic the range, introducing them into new areas, relocating individuals to zoos or aquaria, banking a species DNA, or allowing them to become extinct. The Fish and Wildlife Biologist suggests the solution depends as much on ethics as it does logistics. And that the answer should be dependent on “an all-of-society response.”