More than 200 bottlenose dolphins spent a second day penned in a cove by Japanese fishermen , U.S. conservationists said Sunday , many of them stressed and bloodied from their attempts to escape . The dolphins will spend a third night without food or rest in Taiji Cove before the fishermen likely start to slaughter them Monday for meat , the Sea Shepherd Conservation Society said . Until now , the fishermen have focused on selecting dolphins to be sold into captivity at marine parks and aquariums in Japan and overseas , the conservation group said . Twenty-five dolphins , including a rare albino calf , were taken on Saturday `` to a lifetime of imprisonment , '' and another 12 on Sunday , the group said . Two dolphins have died in the process . Environmental activists have been monitoring activities in the cove in southwest Japan , which is a focal point of the Taiji community 's annual dolphin hunting season . Although the hunting of dolphins is widely condemned in the west , Japanese defend the practice as a local custom -- and say it is no different to the slaughter of other animals for meat . Caroline Kennedy , the recently installed U.S. ambassador to Japan , tweeted that she is `` deeply concerned by inhumaneness of drive hunt dolphin killing . '' The Sea Shepherd Conservation Society has been live-streaming video of events in the cove and posting frequent updates on Twitter . `` Many of the 200+ Bottlenose dolphins who are in still the cove are visibly bloody & injured from their attempts to escape the killers , '' one update Sunday said . Another appealed for people to do their part to end the demand for dolphins captured from the wild . `` Dolphin slaughter in Taiji continues because of the captive trade . Please do not support aquariums & parks with marine mammals , '' it said . Opinion : Eat fish , kill a dolphin ? Slaughter under tarpaulins . The dolphins earmarked for slaughter include those with nicks or markings which make them less desirable as captives . The Sea Shepherd Conservation Society described how about 40 to 60 local fishermen work with nets to divide up the pod , whose initial numbers were estimated by the group at more than 250 . `` They tighten up the nets to bring each sub-group together then the skiffs push them toward the tarps . Under the tarps in the shallows is where the trainers work with the killers to select the 'prettiest ' dolphins which will sell and make the best pay day for the hunters , '' the group said . `` But the process is brutal and stressful . Some of them die from injuries incurred during the manhandling or simply the stress . '' Once the slaughter begins , it will turn the water in the cove red with blood , as documented in footage captured by the Sea Shepherd Conservation Society in the past . The fishermen will `` kill the 'undesirable ' dolphins ( those with nicks and scars ) under the tarps to hide from our cameras when that time comes , '' the group said . Officials say criticism is biased , unfair . CNN has been unable to reach anyone at the town office for Taiji , a community of about 3,000 that juts into the Pacific Ocean , or the local fishermen 's union for comment . But local officials have reacted angrily in the past to Western criticism of what they say is a traditional practice dating back centuries . A 2009 Oscar-nominated documentary film , `` The Cove , '' brought the issue of dolphin hunting in Taiji to the fore with bloody scenes of dolphin slaughter . The Wakayama Prefecture , where Taiji is , condemned the film in an online response as distorted , biased and unfair to the fishermen . `` The Taiji dolphin fishery has been a target of repeated psychological harassment and interference by aggressive foreign animal protection organizations , '' it said . `` Taiji dolphin fishermen are just conducting a legal fishing activity in their traditional way in full accordance with regulations and rules under the supervision of both the national and the prefectural governments . Therefore , we believe there are no reasons to criticize the Taiji dolphin fishery . '' The Japanese practice of whale hunting has also put it in conflict with the views of much of the world . Japan 's fleet carries out an annual whale hunt despite a worldwide moratorium , taking advantage of a loophole in the law that permits the killing of the mammals for scientific research . Whale meat is commonly available for consumption in Japan . Environmental activists warn that dolphin meat , also sold for consumption in Japan , contains dangerously high levels of mercury and other toxins . CNN first learned about this story through a CNN iReport posted by Martha Brock , an environmental attorney and activist in Georgia . `` There are activists around the world that are calling the embassy and the press , but I knew I could n't do much , so I wrote this iReport , '' she said .
Fishermen have taken 37 bottlenose dolphins to be sold into captivity , conservationists say . Many of the 200 dolphins still in the cove in Taiji , Japan , will be slaughtered , they say . Local officials have previously defended hunting of dolphins as a traditional practice . Environmental activists say dolphin meat contains dangerously high levels of mercury .