by Matt Lee
The common thresher (Alopias vulpinus) is a widely dispersed species of shark that inhabits oceans all around the globe. However, because of the species’s high value as a marketable commodity, populations of the common thresher are currently being exploited to irreversible levels. The key obstacle to preventing exploitation is the dearth of quantitative knowledge of shark population numbers, which is the result of unreported target and bycatch fishing of the animal. As an apex predator, the common thresher plays a key regulatory role in countless marine ecosystems, and its removal could produce negative consequences worldwide. More research must be performed to establish the actual extent to which commercial fisheries effect population numbers. With such research completed, scientists and policy makers could better establish conservation goals and manage resources to better protect the species, which is already on the path to extinction.
Found in all tropical and warm-temperate seas worldwide, the whale shark is known as the largest fish in the world, yet it is also one of the least-known shark species. This biologically unique species is declining in numbers due to its vulnerability to exploitation because of its large size, slow growth, and late maturation. Moreover, disturbances to their ecosystems are impacting their migration, feeding, and mating patterns. Nevertheless, current information (reliable scientific data) on their migration routs is insufficient for conservation policies to be created and most research methods are limited. This is why I am proposing to use a satellite transmitter tagging method to study the migration patterns and correlated genetic variability within whale sharks. This will be done by tagging and extracting skin tissue from the same specimen in order to follow their migration tracks via satellite data and analyzing their DNA. After analyzing and interpreting my data I expect to show that whale sharks are able to travel long ranges through multiple political jurisdictions, thus confirming the need to manage the populations on an international level.
Hector’s dolphin (Cephalorhynchus hectori), a species endemic to the waters of New Zealand, is on the road to extinction due to gillnet bycatch. This has resulted in much conflict between fishery interests and wildlife advocacy groups, not to mention the loss of a species. Currently, the government has designated sanctuaries for the protection of the dolphins. However, the sanctuaries limit fishermen, not the dolphins from leaving, so bycatch still occurs. The four populations of dolphins are separated, which contributes to genetic invariability and inbreeding because of less migration. To combat these issues, bycatch reduction devices (BRD’s) should be researched in order to change the design of gillnets. Such modifications have been implemented with fyke nets and have shown considerable success. Implementing BRD’s would limit bycatch as well as decrease genetic invariability through an artificial “baiting” method. With the success of a critically endangered species, the BRD’s can be expanded to other bycatch issues in other waters, helping the fishing economy in the process as well.
Species-centric conservation plans can have disastrous effects on the ecosystem surrounding their target species. With all of the endangered species listed today the countless other candidate species for listing, conservation conflicts are inevitable. Therefore, we must develop ecosystem-centric conservation plans.
This effect is especially apparent in island ecosystems due to their unique, delicate nature. For example, when the San Clemente loggerhead shrike was listed as endangered in the California Channel Islands, its conservation plan called for the removal of the bird’s predators. As predators, island foxes were removed by euthanasia and experienced a 40-60% drop in their total population and are currently critically endangered.
The Channel Islands’ ecosystems have been subject to further degradation by the introduction of non-native golden eagles and feral pigs. The eagles prey on island foxes, further decreasing their already strained populations. Feral pigs supplement the eagles as a prey animal and have made it possible for them to colonize the islands.
If the Channel Islands lose their top natural predator, their ecosystems will never be able to return to their natural states. Therefore, an ecosystem-centric recovery plan must be applied to the Islands to provide for the removal of non-native species and the recovery of the island fox.
Genetic testing, the most modern and accurate method of identification has great but underutilized potential in the conservation of biodiversity. Just last month, the United States Fish and Wildlife Service (USFWS) declared the Eastern cougar extinct based on a five-year study. While this study and judgment of claimed sightings seems like satisfactory evidence, Dr. Melanie Culver’s DNA test offered an entirely new perspective. After discovering the strikingly similar genetics of cougars throughout North America, she made the radical conclusion that Eastern cougars never existed as a distinct subspecies, but are instead part of a larger North American cougar species. As a result, we can use our knowledge of the causes of Eastern cougar extinction to guide us in the conservation of other cougars. DNA analysis exposes the fallacies of the previously employed phylogenic methods and the need to reclassify species via genetic relationship. This information can aid in extinction prevention so that we can limit the number species to which we must say ‘good-bye.’
Madagascar’s endangered species have long suffered from habitat destruction. One such endangered species is the aye aye, a unique lemur with countless evolutionary adaptations. The issues facing the aye aye are not limited to just habitat destruction, however. Native superstition of the animal has led to its intentional persecution. I propose research intended to determine the impact of these killings on overall aye aye populations.
Research would be characterized by extensive field work followed by population models. If the research indicates that murder has a significant effect on aye aye populations, then we should educate the Madagascar natives about biodiversity. Conservation education illuminating the qualities of the aye aye would eradicate superstition and protect its populations.
By Alissa Wall.
The Japanese dolphin slaughter is decimating coastal populations of dolphins, yet it is unregulated by the International Whaling Conference (IWC). Emotionally charged pleas have yet to stop the unethical killings. Because wildlife conservation acts at the species level and because dolphins are comprised of many non-endangered species, a new method to conserve populations is needed. If individual populations of dolphins are demonstrated to exhibit unique cultures, then the destruction of individual populations parallels human genocide. A strong case could thus be made to extend the conservation of biodiversity to include the preservation of culture.
Several studies have been designed to determine whether dolphins exhibit cultures analogous to those of apes. Quantitative and qualitative data will be collected in individual neurophysiology, intrapopulation interactions, and interpopulation interactions. The data will be analyzed and presented to the IWC with the goal of effecting policy change that protects dolphins from unnecessary destruction due to their advanced cognitive abilities and distinctive cultures.
By Caroline Seng
Buff-headed capuchins are the rarest species of New-world primate. Their elusive nature and disturbingly low numbers results in less-than-adequate research opportunities. The scant research accumulated indicates that buff-headed capuchins are exclusively located in mature, old-growth forests and avoid habitat influenced by humans. Very little is known of their ecology. Studies on other capuchin species indicate that a majority of daylight hours are spent foraging. Research must therefore be conducted to define the relationship between movement and foraging.
In my proposed study, individuals from different social groups will be tagged with radio-GPS collars and their movements tracked over a period of time to determine daily and seasonal movement patterns. Many non-invasive analysis techniques, including radar tracking and surveying, will be employed to gather data on the relationship between movement and foraging. This new information can be used to inform conservation decisions. Conserving this species of capuchin will preserve a crucial link to the human evolutionary past.
Gorillas are threatened with extinction unless steps are taken to prevent the spread of the Ebola virus within the species. While gorillas are also threatened by habitat loss and poaching, extensive research has already been conducted on these topics and steps are being taken to reduce these threats. To limit the spread of the Ebola virus, more information needs to be collected on the mechanisms that spread the Ebola virus. Field studies should be conducted to determine whether the virus is being spread through a carrier species such as the fruit bat, or whether it is being spread primarily through interactions between population groups. It is important to gain this knowledge since it could not only help save gorillas, but also save humans as well since the Ebola virus is also a deadly disease that decimates human populations.