“Makoa” RL36 is the 3rd pup death on O’ahu of 2019. Out of the 5 born this year, only two are still alive. How did we get here? Read on to learn about this endangered mammal and what is causing their decline.
About the Hawaiian Monk Seal
The Native Hawaiian Monk seal is a rare, but ancient animal. It is thought to have migrated to Hawaiian waters some 10 million years ago, making its way from the Mediterranean through the Central American Seaway and into the Pacific. There were evolutionary changes along the way as well, with the original Mediterranean Monk Seal evolving into the Caribbean Monk Seal upon arrival in the Western Atlantic. Once the seals passed through the Central American Seaway and into the Pacific, the Hawaiian Monk Seal evolved into its own, separate species, which exists to this day.
The ancestors of this seal represents great loss. Only 400 Mediterranean Monk Seals survive today, and the Caribbean Monk Seal is officially extinct. The last sighting of one was in 1961. Amazingly, in a span of just 100 years, from 1800-1900, a robust Caribbean Monk Seal population of over 300,000 seals was totally decimated by European colonization, as people began hunting them for food, and in pursuit of their blubber to create oil (U.S. Fish and Wildlife, 2012). Unfortunately, these seals did not have an evolutionary fear of humans, and since they spend 1/3 of their lives sleeping on the beach, they made for an easy target for hunters. With the rapid pace of industrialization and consumerism, sadly their fate was quickly sealed.
Why are the Seals Dying?
Unfortunately, the combination of being slow moving on land, shore-dwelling, protein-rich with valuable blubber has made the Native Hawaiian Monk Seal face similar struggles to is cousins to the West. The seals were ruthlessly hunted upon the arrival of humans to the archipelago, and today have a population of only 1400–making it one of the most critically endangered animals in the world. 1100 of these seals inhabit the Northwestern Hawaiian islands, with about 300 on the main Hawaiian islands. There are around 45 “O’ahu” seals that we track and monitor, but that number can vary widely given any particular time of year.
The struggles for the Monk Seals no longer come from hunting. As an officially endangered animal, they are federally protected. In fact one Hawai’i man was recently sent to jail for four years for getting drunk and punching a pregnant monk seal. Although there are upwards of 13 unsolved monk seal murders (I recommend this brilliant article by Jon Mooallem to learn more about that), most monk seal deaths do not occur directly by human hands, but from the industries and effects of their actions. Read on to learn about the 3 largest threats to the Hawaiian Monk Seal.
Marine Debris Entanglement
Industrial fishing nets, ropes and baskets are the most commonly found large debris in Hawaiian waters. Industrial fishing nets, when they become broken or stuck, are often cut and thrown overboard into the ocean when they are no longer useful. These debris inevitably find their way to shore, where they become small ecosystems for fish and wildlife. often monk seals will explore these ghost nets for food, becoming entangled and eventually drowning (seals can only hold their breath for up to 20 minutes).
Competition For Space and food
While the monk seal population is growing on the main Hawaiian islands, the population on the Northwestern islands is shrinking. The atolls of the northwest archipelago are eroding and disappearing every year due to climate change. Food stocks have decreased. Increasing numbers of conflicts between seals for resources or mates have been documented, suggesting that long-term habitation in the region for seals is likely untenable. Re-location efforts to move seals from the NW islands continues to be discussed, but it appears many seals accomplish the migration naturally as a response to growing conflict and resource depletion.
Toxoplasmosis is a parasite that replicates in the guts of cats. On O’ahu alone, there are upwards of 400,000 feral cats–along with domesticated cats that owners allow outside–that often defecate outdoors, spreading the parasite into ground water, streams, and eventually the oceans. The parasite then accumulates near the shore, where many monk seals choose to hunt. Monk seals have no natural protection against toxoplasmosis, and once contracted, death is largely certain. In 2018, we lost 3 seals on O’ahu to toxoplasmosis. Efforts to reduce feral cat populations or to make feeding feral cats illegal is often met with extreme protests, so the cat population continues to grow while these rare animals slink towards extinction.
What happened to Makoa (RL36)?
Makoa was born on Mother’s Day, 2019 to Honey Girl (read about her amazing story here), one of the oldest documented seals in the wild and mother to 12 pups. Unfortunately, as of today, only two of those pups are still alive following the death of Makoa. NOAA reports the initial assessment of how the pup died are inconclusive. NOAA is famously protective of any information that goes out about the seals, so you can expect them to remain tight-lipped until final diagnostics are in place. Unfortunately, sometimes they can never determine the cause of death. Along with the aforementioned threats to the seals, things like infections, trauma from boats, other seals, or even waves can all contribute to high mortality rates.
It has truly been a sad year for the monk seals, as so much effort and work has been put into conserving these animals. We can only hope for a better year next year, with more serious measures put in place to slow climate change, address the spread of toxopasmosis, and limit the amount of fishing gear in the ocean.
A hui hou, Makoa.