Claim: Scientists debate cause of dolphin deaths.
Verdict: SUPPORTS

Retrieved passages:
title: Maui's dolphin
text: not have their cause of death assessed or it was unknown. Six deaths were linked to possible or known net entanglement, six deaths to natural causes, and two deaths to human interaction. Dolphins can get entangled in fishing nets and drown. The DOC Incident Database contains no reports of a Māui's dolphin mortality in a trawl net. Some groups in the fishing industry are against increased bans on set nets into waters further offshore and inside harbours, and say other factors are responsible for the decline in the population, including disease, pollution, mining, and natural predation. Since the first major

title: Chilika Lake
text: deaths in 2003-04, 11 in 2004-05, 8 in 2005-06 and 5 in 2006-07. 40% of the 2006-07 deaths were by mechanised boats. Since 2004, the Whale and Dolphin Conservation Society has been conducting a science-based community education project to conserve the Irrawaddy dolphins and Chilika Lake. They have determined the primary cause of mortality for this population of dolphins is floating gill nets and hook line fisheries and the secondary cause is boat strikes from increasing unmanaged tourism activities. The Irrawaddy dolphins have a seemingly mutualistic relationship of co-operative fishing with the traditional fishermen. Fishermen recall when they would call

title: Dolphin Research Center
text: "Sun-Sentinel" alleged that the Dolphin Research Center failed to report the birth and death of a dolphin calf to the National Marine Fisheries Service in 2001, nor did it report the birth of a calf in 2002. The National Marine Fisheries Service is required to keep a record of captive marine mammal births, deaths, and transfers in the United States. After Hurricane Andrew struck the Florida Keys in 1992, the DRC dolphin "Annessa" escaped or was washed out of her sea pen. Opponents of dolphin captivity including Ric O'Barry allege that Annessa is an example of a captive-born dolphin successfully

title: Flora and fauna of Odisha
text: impact dolphin behavior and cause several accidental dolphin deaths each year. CDA conducts an annual census of dolphin deaths. They report 15 deaths in 2003–04, 11 in 2004–05, 8 in 2005–06 and 5 in 2006–07. 40% of the 2006–07 deaths were by mechanised boats. Since 1984, the Whale and Dolphin Conservation Society has been conducting a science-based community education project to conserve the Irrawaddy dolphins and Chilika Lake. They have determined the primary cause of mortality for this population of dolphins is floating gill nets and hook line fisheries and the secondary cause is boat strikes from increasing unmanaged tourism

title: Environmental impact of the Deepwater Horizon oil spill
text: February is not even over yet." From mid-January to late March 2011, scientists counted almost 200 dead dolphins in the Gulf, with another 90 in 2010. After investigating the deaths, NOAA put a gag order on the results, saying that the research is part of a criminal investigation of the spill. Numerous independent scientists said they have been "personally rebuked by federal officials for speaking out of turn to the media about efforts to determine the cause" of the deaths. In April 2011, one year from the onset of the spill, scientists confirmed that they had discovered oil on dead

title: Taiji dolphin drive hunt
text: dolphins may officially only be killed by driving a metal pin into the neck of the dolphin, which causes them to die within seconds according to a memo from Senzo Uchida, the executive secretary of the Japan Cetacean Conference on Zoological Gardens and Aquariums. A veterinary team's analysis of 2011 video footage of a Japanese hunters killing striped dolphins using this method suggested that in one case death took over four minutes. A few dolphins from each hunt may be selected for captivity and sold to marine parks around the world. In May 2015, the World Association of Zoos and

title: Maui's dolphin
text: is contrary to a NABU paper submitted to the Scientific Committee of the International Whaling Commission in June 2013, which referred back to the database that the number of fatal Māui's entanglements in fishing nets has increased, from an average of one per year, to 1.33 per year, since 2008. In 2012, the majority of a government-appointed panel of experts estimated that set-netting and trawling resulted in an average of five Māui's dolphin deaths each year. In 2006, "Brucella" was found in a dead Māui's dolphin and DOC says this bacterial infection could have serious ramifications for the small Māui's

title: Harmful algal bloom
text: are caused by harmful algal blooms. In 1999, over 65 bottlenose dolphins died during a red tide in Florida. In 2013 a red tide in southwest Florida killed a record number of Manatee. Whales have also died in large numbers. During the period from 2005 to 2014, Argentina reported an average 65 baby whales dying which experts have linked to algal blooms. A whale expert there expects the whale population to be reduced significantly. In 2003 off Cape Cod in the North Atlantic, at least 12 humbpack whales died from toxic algae from a red tide. In 2015 Alaska and

title: Bottlenose dolphin
text: killed harbour porpoises. University of Aberdeen researchers say the dolphins do not eat their victims, but are simply competing for food. However, Dr. Read of Duke University, a porpoise expert researching similar cases of porpoise killings that had occurred in Virginia in 1996 and 1997, holds a different view. He states dolphins and porpoises feed on different types of fish, thus food competition is an unlikely cause of the killings. Similar behaviour has been observed in Ireland. In the first half of July, 2014, four attacks with three Porpoise fatalities were observed and caught on video by the Cardigan Bay

title: Deepwater Horizon oil spill
text: oil and dispersants to coral also found that the dispersants were more toxic than the oil. A 2015 study by the National Oceanic and Atmospheric Administration, published in "PLOS ONE," links the sharp increase in dolphin deaths to the "Deepwater Horizon" oil spill. On 12 April 2016, a research team reported that 88 percent of about 360 baby or stillborn dolphins within the spill area "had abnormal or under-developed lungs", compared to 15 percent in other areas. The study was published in the April 2016 " Diseases of Aquatic Organisms". By June 2010, 143 spill-exposure cases had been reported to

title: Maui's dolphin
text: restrictions on commercial fishing to protect Māui's dolphins were imposed in 2003, 12 mortalities have been listed along the west coast of the North Island. Of these, three have been confirmed as Hector's dolphins and the deaths of all but one were from natural causes. The single death attributed to fishing occurred in January 2012. The most recent dolphin death reported was from old age, with no indications of fishing injury, and she was found on a beach near Dargaville on 13 September 2013. An analysis of microsatellite DNA shows the dolphin was a Māui's. This DOC Incident Database information

title: Hardy Jones
text: as the efforts of BlueVoice.org to end the killing of dolphins in Japan and the increasing menace of chemical contaminants in the marine food chain. In 2003 Jones was diagnosed with multiple myeloma, a form of blood cancer often linked to exposure to toxic chemicals such as dioxins. His recent work was researching the relationship between persistent organic pollutants to cancer and other health problems in humans and marine mammals. Jones fought for nearly thirty years to stop the killing and capture of dolphins in Japan and worked on environmental issues in Peru for more than five years. He documented

title: Deepwater Horizon oil spill
text: contained within the spill-affected area. In March 2012, a definitive link was found between the death of a Gulf coral community and the spill. According to NOAA, a cetacean Unusual Mortality Event (UME) has been recognized since before the spill began, NOAA is investigating possible contributing factors to the ongoing UME from the Deepwater Horizon spill, with the possibility of eventual criminal charges being filed if the spill is shown to be connected. Some estimates are that only 2% of the carcasses of killed mammals have been recovered. In the first birthing season for dolphins after the spill, dead baby

title: BP
text: say the oil and dispersant mixture, including PAHs, permeated the food chain through zooplankton. Toxicological effects have been documented in benthic and pelagic fish, estuarine communities, mammals, birds and turtles, deep-water corals, plankton, foraminifera, and microbial communities. Effects on different populations consist of increased mortality or as sub-lethal impairment on the organisms' ability to forage, reproduce and avoid predators. In 2013, it was reported that dolphins and other marine life continued to die in record numbers with infant dolphins dying at six times the normal rate, and half the dolphins examined in a December 2013 study were seriously ill or

title: Environmental impact of the Deepwater Horizon oil spill
text: lungs. In December 2013, the journal "Environmental Science & Technology" published a study finding that of 32 dolphins briefly captured from 24-km stretch near southeastern Louisiana, half were seriously ill or dying from liver disease, pneumonia, loss of teeth, and one pregnant female was carrying a dead fetus. The animals compared unfavorably with dolphins from an area of the gulf unaffected by the spill. BP said the report, which was the first study of the spill's impact on dolphins, was “inconclusive as to any causation associated with the spill”. On 12 April 2016, a research team reported that 88 percent

title: Cetacea
text: mass strandings of pilot whales and sperm whales. Stranded cetaceans usually die, because their as much as body weight compresses their lungs or breaks their ribs. Smaller whales can die of heatstroke because of their thermal insulation. The causes are not clear. Possible reasons for mass beachings are: Since 2000, whale strandings frequently occurred following military sonar testing. In December 2001, the US Navy admitted partial responsibility for the beaching and the deaths of several marine mammals in March 2000. The coauthor of the interim report stated that animals killed by active sonar of some Navy ships were injured. Generally,

title: Bottlenose dolphin
text: dolphins that could be killed yearly by tuna fishing crews. Dolphins in the United Kingdom have also been found to contain high levels of pollutants in their tissues. Heavy metals including mercury, PCB's and DDt are of great concern. These pollutants can cause harm in the dolphins growth development, reproduction, and immunity. Since the mid -1990s, hundreds of dolphins have been trained to perform in shows presented by aquariums, zoos, and amusement parks. Scientists conduct various types of research to understand the dolphins communication system. The man-made chemical perfluorooctanesulfonic acid (PFOS) may be compromising the immune system of bottlenose dolphins.

title: Environmental impact of the Deepwater Horizon oil spill
text: sample of pelican eggs tested contained "petroleum compounds and Corexit". As of 2 November 2010, 6,814 dead animals had been collected, including 6,104 birds, 609 sea turtles, 100 dolphins and other mammals, and 1 other reptile. According to the U.S. Fish and Wildlife Service, cause of death had not been determined as of late June. According to NOAA, since 1 January 2011, 67 dead dolphins had been found in the area affected by the spill, with 35 of them premature or newborn calves. A NOAA study in spring 2012, along with two other studies reported at the same time, suggest

title: Striped dolphin
text: behavioral changes. This has also been suggested as another reason for mortality events. The striped dolphin was once thriving with 117,880 individuals before 1990. Since then, they had suffered a large-scale epizootic event by incidental catches from fisheries. The mortality have been considered unsustainable; although the lack of data is the chief contributor of why this is the case, resulting in unreliable data, and thus lack of knowledge on where to start conservation efforts for the striped dolphin. Various stranding over the years have caused for alarm. With an unfavorable conservation status and the increasing amount of debris piling in

title: Pantropical spotted dolphin
text: in the Pacific Islands Region" (Pacific Cetaceans MoU). The U.S. Marine Mammal Protection Act was established in 1972. U.S. Fishing vessels have since reduced dolphin by-catch deaths by 95%. The U.S. Marine Mammal Protection Act lists the northeastern and coastal stocks as “Depleted.” Dolphin deaths have greatly decreased since the establishment of the Inter-American Tropical Tuna Commission (IATTC). The Commission set mortality limits on the international fleet. In 2005, only 373 spotted dolphin deaths were observed. Dolphin populations are able to grow at 4% per year, but the pantropical spotted dolphin populations did not improve or worsen between 1979 and