Comment by Anonymous on 0648-AW32

I agree with and support the proposal from the National Marine Fisheries Service and the National Oceanic and Atmospheric Administration to put the black abalone on the endangered species list. The black abalone is susceptible to many harmful threats. The largest threat to the black abalone is the disease “withering syndrome” (also known as abalone wasting disease) which attacks the abalone digestive tract. The black abalones basically wither away. Their muscular foot, which aids in their movement, wastes away completely and they consume their own body. Global climate change and a changing habitat are creating unhealthful and unfavorable conditions for the black abalone to survive and reproduce. Also, fishing and sea otters contribute to the decline black abalone population, since both the sea otters and the humans, through fishing activities, are killing them. The sea otters feed on the black abalones and the fishing disrupts the abalone population and habitat. The black abalone should be listed as endangered so it can be protected from withering syndrome disease, global warming effects, and fishing and other predators. The black abalone will benefit from being put on the endangered species list. Listing species as threatened or endangered can help to restore populations and habitats. Although many species remain on the endangered or threatened lists, several species have regained in numbers and have been delisted (Doremus & Pagel, 2001). Listing the black abalone as endangered will hopefully help them to increase their population so they have a sustainable population and can be removed from the Endangered Species list. In the journal article The Effectiveness of the Endangered Species Act: A Quantitative Analysis it says that with good recovery plans a species can have a good chance at survival (Taylor, Suckling, & Rachlinski, 2005). Once listed, researchers can develop a successful black abalone recovery plan which will increase the chances of survival. There are so many things negatively impacting the black abalone population that listing them as endangered can only be a positive impact, by helping to protect the small population that is left. With a well thought out plan for black abalone recovery the species could regain its numbers and be on the way to survival. Withering Syndrome Withering syndrome is the largest reason that the black abalone should be considered endangered. Withering syndrome is a disease caused by a Rickettsia- like prokaryote (RLP) and it has almost completely eliminated the black abalones (California Department of Fish and Game, 2001). If nothing is done to protect the black abalones, then an outbreak of withering syndrome could potentially cause them to become extinct. Friedman and Findley (2003) found that the RLP is found in over 70% of all types of abalones south of San Francisco. Most if not all black abalone live south of San Francisco, which according to the study is greatly affected with the bacteria that causes withering syndrome. In black abalones specifically, withering syndrome is killing over 90% of the species (Roach, 2005). That is such a large percentage to be affected by the disease that eliminating it alone will significantly help to increase the black abalone population. Disease rates must be taken into consideration when forming plans to help the black abalones populations (Friedman & Finley, 2003). Black abalones need to be protected from withering syndrome since it is killing so many of them, but since it is not directly caused by humans it would be something that is hard to manage through regulations. Once the black abalone is recognized as endangered more research can be put into withering syndrome. Several black abalones have been discovered in San Nicolas Island in California that are resistant to withering syndrome (Johnson, 2007). Scientists believe they are resistant because that area has been exposed to high levels of the disease and its black abalones have survived due to the high selective pressures (Johnson, 2007). This information can be very useful in helping to repopulate the black abalone species especially since disease is the largest threat. They are trying to breed these disease resistant abalones so they can release them to help the abalones’ survival (Johnson, 2007). Breeding the black abalones that are resistant to withering syndrome could be incorporated as a large part of the recovery plan. The resistant genes and characteristics would get passed on and more abalones would be able to survive the disease. Scientists are researching and developing a treatment for withering syndrome which could help the black abalone survive to reproduce and increase their population. The antibiotic oxytetracycline (OTC) can be given to abalones to cure the disease (Johnson, 2006). It has been used on abalone farms, but the antibiotic stays in the abalones system for a while so treated abalone cannot be sold until the antibiotic levels are low enough (Johnson, 2006). The antibiotic could be effective in helping the black abalone species. If abalones are captured, treated, and then released back into their environments they might be able to survive and withstand the bacteria that causes withering syndrome (Johnson, 2006). A study, on the effects the antibiotic oxytetrcycline has on red abalone in different water temperatures and on the progress of the disease, shows that the treated abalones had much lower signs of disease, than the untreated abalones (Rosenblum, Tjeerdema, & Rachlinski, 2006). This study shows that the antibiotic does work on curing withering syndrome and could help to protect and save the black abalone species if they receive the treatments. Using the antibiotic and studying the disease resistant abalones could be a big part of the abalone recovery plan. Changes in Climate Increased water temperature also causes the bacteria that cause withering syndrome to spread more rapidly through the black abalone population (California Department of Fish and Game, 2001). The warm water allows the bacteria to survive longer and infect more black abalones than if the water was not as warm (Johnson, 2006). As the climate changes and the ocean water gets warmer, withering syndrome will spread to more northern waters and affect the abalones that live in those habitats (Roach, 2005). As the water increases in temperature even more abalones are put at risk for the Rickettsia-like prokaryote resulting in disease. Withering syndrome which already kills so many black abalone will only spread and increase with the warming of ocean temperatures. The increasing ocean temperatures caused by global warming and climate change affect the black abalone populations. The water temperature affects the growth and reproduction of the abalones. Higher water temperatures have fewer nutrients which the black abalone need than cooler waters. Also the food that the abalone eat such as kelp, cannot survive the warmer temperatures so there is less food for the abalones (California Department of Fish and Game, 2001). The small amount of nutrients and food found in warmer waters cause fewer abalone to be able to survive these conditions. The warmer the water gets the less food and nutrients there are for the black abalone. The changing environment and habitat causes the black abalone to have to compete more for food since there is a limited supply. Other causes of changes in water temperature can be more locally caused. Power plants that release warm water into the ocean are affecting the black abalone’s habitat as well. In the 1980s, many abalones died in the surrounding waters of the Diablo Canyon nuclear power plant (Weiss, 2008). Listing the black abalone as endangered could tighten restrictions on warm water being released into the ocean. Predators of the Black Abalone Overfishing is a large issue affecting all the different kinds of abalone. In 1997, commercial and sporting fishing of abalones in southern California was banned due to the declining populations (California Department of Fish and Game, 2001). Many abalones are preyed upon by either humans, through fishing or sporting activities, or other animal predators, often before they can reproduce. In addition to fishing practices humans also disrupt black abalone habitat causing strain to the species. Several predators of the abalones are crabs, lobsters, octopuses, gastropods, sea stars, sea fishes, and mainly sea otters (California Department of Fish and Game, 2001). Sea otters are the most common predator for the abalones. Increasing sea otter populations have also caused a part in the decline of the black abalones. The more sea otters there are the more food they need to consume. Since they are eating more and their food source is the abalones then more abalones are being preyed upon and killed. If nothing is done to protect the black abalone then the few members of the species left could become extinct due to predators alone. Poaching of black abalones may not be an issue in the United States, but abalone poaching has become popular in other areas such as South Africa and some Asian countries (Wines, 2006). People see abalones as a delicacy and they can be rather valuable. Poaching is a large business and is hard to control (Wines, 2006). The black abalones should be placed on the endangered list so they can be strongly protected against poaching and other harmful human activities. Black Abalone Reproduction Another issue with the black abalone status is the way they reproduce. The abalones release their sperm and eggs directly into the water. In order for them to reproduce the abalones must be close to each other and not so far spread out to increase the chances of fertilization to occur, even just three or four feet is too far (California Department of Fish and Game, 2001). The less black abalone there are the less likely they are to reproduce since they are spread out more. The black abalones need to be protected. There are so few numbers that they are not close enough to reproduce successfully. Abalones reach maturity at around three years. Since many black abalones do not survive long enough to reproduce and the ones that do survive are not close enough to reproduce, the species is suffering. It is also hard to recreate the intertidal conditions for the black abalones to be bred in captivity (Johnson, 2007). Something needs to be done to increase the amount of black abalones so they can reproduce successfully on their own, since it cannot be done in captivity the same way. Conclusion I believe the black abalone should be listed as endangered under the Endangered Species Act. Listing the black abalone as endangered is the only hope for black abalone survival. Once listed a plan needs to be developed to control black abalone population and habitat. Since there is already treatment for the main cause of black abalone deaths, withering syndrome, then a successful recovery plan should be well attainable. The information and research that is already been done about the oxytetracycline antibiotic and the disease resistant black abalones should be enough to get a good start at recovering and protecting the black abalone population. Also habitat restrictions and fishing regulations will help to maintain the few black abalone that are left until the species recover to a greater number and fuller population. Black abalone will be better protected from predators, disease, and climate changes once listed under the Endangered Species Act as endangered. I strongly encourage that the black abalone join the already listed white abalone on the endangered species list so it can hopefully be protected and be around for many years to come. The black abalone does not have to become extinct; many of the threats to the black abalone are human introduced. If we do something now we can help by reducing the already existing threats and by preventing any new threats that could develop. Listing the black abalone as endangered is the first step in its recovery.