由于只有少数几个潜水员进行捕捞，而且他们会注意不造成过度捕捞的现象，所以潜水员的持续活动显然不会对公主鱼种群造成严重危害。
Since the divers limit their catch to a few individuals and take care not to overfish, the divers' continuing activities will clearly not result in serious harm to populations of princessfish.
四齿鲀科族里共有超过90个河豚鱼种类。
There are over ninety species of pufferfish all belonging to the family Tetraodontidae.
这在导致整个鲑鱼种群灭绝的案例中最为明显。
This is most evident in cases where it results in the extinction of entire salmon populations.
事实上，大多数分析家认为某种环境退化是许多已灭绝鲑鱼种群消亡的根源。
Indeed, most analysts believe that some kind of environmental degradation underlies the demise of many extinct salmon populations.
清除淤泥，发现鱼类产卵的砾石层，找到合适的鲑鱼种类来重建种群是一项艰巨的任务。
Removing the mud, uncovering gravel beds where fish spawn, and finding suitable salmon types to rebuild the population is a daunting task.
1月在美国杂志《科学》上发表的一项研究发现，在过去8至15年间，几乎所有有记录的鲨鱼种类的数量都减少了一半。
A study, published in January in the US magazine, Science, found that almost all recorded shark species have fallen by half in the past 8 to 15 years.
这一点很重要，因为理论表明，当目标鱼种的生物量为其原始水平的50%左右时，渔场才能达到可收获的最大可持续产量。
That matters because theory suggests that the maximum sustainable yield that can be cropped from a fishery comes when the biomass of a target species is about 50% of its original levels.
有时他们吃掉幼小的竞争鱼种。
他们还要提供捕鱼活动和所载鱼种的信息。
They would also have to provide information on their activities and the fish they are carrying.
潘兴说，碳信用可为恢复鱼类和鲸鱼种群提供额外奖励。
Carbon credits could provide additional incentive to rebuild fish and whale populations, Pershing says.
特别美丽的青枪鱼是最大的大西洋的马林鱼，是世界上最大的鱼种之一。
The strikingly beautiful blue marlin is the largest of the Atlantic marlins and one of the biggest fish in the world.
往后，这两位学者将研究当环境的得到清理后此类鱼种再次进化的过程。
After that, the two researchers will be able to look at how these populations evolve yet again as the environment is cleaned up.
那里是位于巴布亚新几内亚的一个原始的珊瑚礁生态环境，是许多鱼种的家园。
This striking blue fish was found in the waters of Milne Bay, Papua New Guinea, a region of pristine reef environments and home to a huge number of fish species.
那里是位于巴布亚新几内亚的一个原始的珊瑚礁生态环境，是许多鱼种的家园。
This striking blue fish was found in the waters of Milne Bay Papua New Guinea a region of pristine reef environments and home to a huge number of fish species.
几年后，当他们把一片海域的珍贵鱼种全都吸光之后，就会转移到一片新的海域。
They move into a new area, within a few years they have cleaned out all these live, valuable fish, then they move on to another area.
这种鱼（假设我们可以真正称它为鱼）使我们之前见过的鱼种长相最奇特的一种。
This fish (if "fish" we can really call it) is the weirdest looking sea creature we've ever seen.
如果人类继续这样的捕杀行为，那么这些鲨鱼种群在几十年内灭绝的风险将相当高。
If we carry on the way that we are, we're looking at a really high risk of extinction for some of these shark species within the next few decades.
过度捕捞不仅引起个别鱼种的消耗，而且还引起海洋中整个生态系统和食物网的崩溃。
Overfishing not only causes depletion in individual fish stocks, but also disruption to entire ecosystems and food webs in the ocean.
研究鲨鱼的科学家艾莉森·科克说，它可能是一条大白鲨，该地区最常见的鲨鱼种类。
Shark scientist Alison Kock said it was probably a great white, the most commonly spotted shark in the area.
意外发生时，考察队伍正在南非开普海岸莫塞尔湾海豹岛附近进行鲨鱼种群数量研究。
The incident occurred while the research team was conducting a shark population study off Seal Island, near Mossel Bay, on South Africa's Cape coast.
此种鱼原产于大西洋、太平洋和印度洋的热带和温带水域中，是所有鱼种中最为知名的。
Native to the tropical and temperate waters of the Atlantic, Pacific, and Indian Oceans, blue marlins are among the most recognizable of all fish.
一个世纪以来，全球湿地消失了一半，淡水鱼种类中超过五分之一已经灭绝或濒临灭绝。
Over a fifth of the world's freshwater fish species of a century ago are now endangered or extinct. Half the world's wetlands have also disappeared over the past 100 years.
太平洋水族馆的芭芭拉。朗说，当鲨鱼种群面临风险时，太平洋的状况也会处于危险之中。
Barbara Long at the Aquarium of the Pacific says when the shark population is put at risk, the health of the ocean is also in danger.
他们的方法并不是要评估特定海域鱼种的实际生物量，而是评估在这一段时间内生物量的变化。
Their methods do not attempt to estimate the actual biomass(the amount of living biological matter) of fish species in particular parts of the ocean,but rather changes in that biomass over time.
他们的方法并不是要评估特定海域鱼种的实际生物量，而是评估在这一段时间内生物量的变化。
Their methods do not attempt to estimate the actual biomass(the amount of living biological matter) of fish species in particular parts of the ocean,but rather changes in that biomass over time.
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