Extinct, Endangered and Threatened Species
An animal is declared extinct when “there is no reasonable doubt that the last individual (of the species) has died” (1). Although extinction is a natural biological process, the rate of extinction and the endangerment of animal and plant species is occurring at an alarming rate due to the growing human population. As the human population increases in size and expands its habitat, natural resources are depleted and strained impacting the earth’s biodiversity. Biologists estimate that the current annual rate of extinction is around 100 times the extinction rate that existed 150,000 years ago—an extinction rate that amounts to 0.01% a year. Some scientists argue that as a result of global warming and other human activities, the actual extinction rate could be anywhere between 0.01% and 1%. According to researchers E.O. Wilson and Stuart Pimm, one-fourth of the world’s animal and plant species could be extinct by 2050 at this rate and nearly half could be extinct by the end of the century (2).
Animal and plant species heading towards biological extinction are classified as either endangered or threatened. Endangered species are species that have so few individual survivors that the species could soon become extinct. A threatened species, on the other hand, is still abundant in the wild, but may soon become endangered (2). In recent years, conservationists have been focusing their efforts on preventing the extinction of endangered species.
Endangered or Threatened Marine Species
It was long thought that the sea, vast and limitless, was the source of inexhaustible resources. In fact, marine species were once thought to be “extinction-proof” because of their huge population sizes, their vast geographical ranges and ability to successfully reproduce. However, more recently, scientists have begun to realize that marine animal extinction has been occurring for years, although at a much slower rate and later than land extinction. Marine species that are particularly vulnerable are those that take a long time to mature, those that have low reproductive rates, species that are able to live in environments with little disturbance and those that are exploited by the human population for profits (3). Many species that have existed for centuries are now facing the threat of extinction including the Chambered Nautilus, Coral, and the Leatherback Sea Turtle.
The Chambered Nautilus
The Chambered Nautilus is a living fossil species which has inhabited the earth for almost half a billion years. The logarithmic shape of the cross-section of the Chambered Nautilus’s shell and its mathematical perfection (it is a living example of the Golden Ratio) has long captivated the notice of people across the world. Historically, the Chambered Nautilus was used as ornamentation—the Medicis in Florence turned the shells into beautiful cups and pitchers covered in gold and jewels. In modern times, the love of the Chambered Nautilus’ unique shell may be responsible for driving the marine animal species towards extinction.
The growth of a jewelry industry surrounding the Chambered Nautilus’ pearly shell is the root cause of the animal’s endangered status. To meet worldwide demand for the shell, scientists maintain that fishermen are killing the animal by the millions. What is particularly frightening is the fact that the Chambered Nautilus takes 15 years or more to reach sexual maturity—a growth rate that does not match the rising demand for the species’ shell. According to Neil Landman at the American Museum of Natural History, “In certain areas, it’s threatened to extermination” (4). After billions of years on our planet, this marine animal species may soon become extinct due to excessive exploitation.
Coral
Another marine plant species for which there is a possibility of extinction are coral reefs. In areas around Southern Florida, there has been a sharp decline in the number of coral reefs in the past 25 years. To the dismay of many environmentalists in the area, Florida’s Department of Environmental Protection is about to grant the Army Corps of Engineers the right to blast the port of Miami to allow space for larger-sized freighters. According to Diego Lirman, a scientist at the University of Miami, prior to the blasting, some of the coral reefs off the shore of Southern Florida close to Miami had already lost 70 to 75 percent of their coral.
The primary motive behind the intended blasting and dredging of Miami’s port is the intense competition that the Miami port is facing against Eastern ports. However, many experts believe that Miami is unlikely to become a hub for shipping because of its less than ideal location at the end of the peninsula (5). As a result, the intended benefit of blasting the area may not actually be worth the associated risks to the environment. According to environmentalists, state officials are currently in the process of creating a plan to mitigate the risks to the seven acres of coral that is expected to be directly affected by the blast. In addition to the damage done to the coral, there are about eight acres of sea grass that are expected to be negatively affected by the planned blasting.
The elkhorn, one particular species of coral responsible for building and stabilizing reefs, has seen its population declining rapidly over the past 25 years as a consequence of storms, disease, and dramatic changes in the ocean’s temperature. In addition, a new study has shown that human fecal matter that seeps from the Florida Keys has had a negative impact on the elkhorn, essentially choking the species and depriving them of nutrients (5). The blasting of the Miami port would add an additional stressor to the coral species in the area.
Kent Carper, the director of the Global Marine Species Assessment program, stated, “When corals die off, so do the other plants and animal that depend on coral reefs for food and shelter, and this can lead to the collapse of entire ecosystems.” Given that over 25% of marine species depend on coral reefs for either food or shelter, the long lasting impact of their destruction is evident (6).
Leatherback Sea Turtles
The Leatherback Sea Turtle, the largest turtle species in the world, is endangered worldwide. Over 65 million years old, the species is now facing the threat of extinction. In 1980, there were over 115,000 adult female Leatherback Sea Turtles, but now there are only 25,000 worldwide (7).
In Costa Rica, the Leatherback Sea Turtle is especially vulnerable to becoming extinct soon. As a result of warming temperatures and rising seas, the sea turtle population has been slowly declining. Sea turtles have also been threatened by beach development, net fishing, and the Costa Rican love for eating turtle eggs.
This species of turtle is affected by global warming in multiple ways. They feed on coral reefs which are slowly dying and lay their eggs on beaches which are being flooded by the rising seas. Perhaps even more worrisome is the fact that the sea turtle gender is not predetermined by their genetic makeup, but by the egg’s temperature during development; warmer temperatures are correlated with primarily female populations, which is problematic for future generations of sea turtles.
In an attempt to battle the dwindling sea turtle population, scientists in Costa Rica are taking matters into their own hands. After a sea turtle lays her eggs, scientists are relocating the eggs to cooler, shadier areas and once the eggs have hatched, they are carried in baskets to the ocean’s edge. Scientists believe that cooler sands alone will not save the species, but that a concentrated effort on the part of governments to create regulations and areas that are safe for the species could help (8).
The Imminent Threat
Dr. Anthony Richardson, from The University of Queensland and the Commonwealth Scientific and Industrial Research Organization (CSIRO), and his co-author, Dr. Elvira Poloczanska from CSIRO in Hobart, both assert, “Marine ecosystems are undoubtedly under-resourced, overlooked and under threat and our collective knowledge of impacts on marine life is a mere drop in the ocean.” They also argued that there was an overwhelming bias toward land-surface studies as opposed to marine-based studies because marine-based studies are often more resource-intensive, expensive and tedious (9). While land-surface studies are important as well, more emphasis must be placed on understanding the impact of human involvement on the real environment and the threat that the shifting environment has on marine species.
Biodiversity in the world’s oceans is decreasing at an unsettling rate; so much so, in fact, that Edward Wilson, a biologist at Harvard University, created a “Hundred Heartbeat Club,” a list of critically endangered species that have populations of 100 or fewer individuals—just ‘heartbeats away’ from extinction. Many biologists also fear that we are entering the period of great mass extinction—perhaps the largest in the world’s history, although different from previous periods of mass extinction in many ways. First, the primary cause of animal species extinction is human activity. Further, the extinction and endangerment of many of the world’s species is occurring in a particularly compressed time frame, unlike previous extinctions (10). More emphasis must be placed on understanding and stopping the rate of extinction for these marine species; otherwise species such as the Chambered Nautilus, Coral, and the Leatherback Sea Turtle, inhabitants of the world for billions of years, will ultimately become extinct.
References
1. M. Etherton, T. Allen. If Animals Could Talk (Ready-Ed Publications, Greenwood, 2007), pp. 10.
2. G. Tyler, S. Spoolman. Sustaining the Earth: an Integrated Approach (Cengage Learning, Australia, 2009), pp. 96.
3. E. Norse, L. Crowder. Marine Conservation Biology: the Science of Maintaining the Sea’s Biodiversity (Island Press, Washington, 2005), pp. 58.
4. W. J. Broad, Loving the Chambered Nautilus to Death (2011). Available at http://www.nytimes.com/2011/10/25/science/25nautilus.html?pagewanted=all (09 December 2011).
5. L. Alvarez, Fears in Miami That Port Expansion Will Destroy Reefs (2011) Available at http://www.nytimes.com/2011/09/04/us/04coral.html?pagewanted=1&n=Top/Reference/Times%20Topics/Subjects/E/Endangered%20and%20Extinct%20Species (09 December 2011).
6. One-third of Reef-Building Corals Face Extinction. (2008). Available at http://www.conservation.org/newsroom/pressreleases/Pages/Reef-Building-Corals-Face-Extinction.aspx (09 December 2011).
7. The Leatherback Trust (2011). Available at http://www.leatherback.org (09 December 2011).
8. E. Rosenthal, Turtles Are Casualties of Warming in Costa Rica (2009). Available at http://www.nytimes.com/2009/11/14/science/earth/14turtles.html (09 December 2011).
9. Ocean Life Under Threat From Climate Change (2008). Available at http://www.sciencedaily.com/releases/2008/06/080606105448.htm (09 December 2011).
10. E. Solomon, L. Berg, D. Martin. Biology (Brooks/Cole Thomson Learning, Belmont, 2005) pp. 1091.
Potential pictures for use:
Chambered nautilus
1. http://www.answersingenesis.org/assets/images/articles/aqua/Chambered_Nautilus.jpg
2. http://martingallerycharleston.com/images/ddb_073_chambered_nautilus_d.jpg
Coral
1. http://green-buzz.net/wp-content/uploads/2011/05/corals.jpg
2. http://cdn.physorg.com/newman/gfx/news/hires/thisundatedu.jpg
Leatherback Sea Turtle
1. http://www.costaricaturtles.org/images/hawksbill.jpg
2. http://www.nytimes.com/2009/11/14/science/earth/14turtles.html