Conserving the critically endangered "river pig"

Poyang Lake--finless porpoise habitat

As I wrote previously, the Yangtze finless porpoise has been moved from Second Class to First Class Protection Status in China. In some ways, this is very good. It means that higher government offices will be responsible for the species' protection. It also means that the work carried out by citizens, environmental organizations, and research institutes has fortunately caught the government's attention and drawn it towards this charismatic and valuable animal.

However, the law does not in and of itself address the issues that are actually impacting the porpoise's population. It seems to focus on direct impacts, in particular poaching or killing for other reasons. Unfortunately, because the porpoise is at the top of its food chain, there are a multitude of direct and indirect factors that threaten its survival. By simply living in and along the Yangtze River, the porpoise continually comes face-to-face with the environmental externalities that accompany economic development. These include pollution, constant sand-dredging, irresponsible fishing practices, boat accidents, and dam-building. Each one of these problems will require a policy to address it along with the monetary and human resources needed to enforce new rules or laws. China has a record of passing laws quickly, but it also has problems with corruption, particularly with environmental regulations.

If officials decide to take control of the situation, they will probably relocate chemical plants rather than try to enforce upgrades. This is one of the actions that they have taken in other cases of extreme pollution problems. (Not my favorite solution, since it is just outsourcing pollution to another poor area or even another country, possibly. This also doesn't address non point-source pollution, which is significant in China.)

Constant sand-dredging, irresponsible fishing accidents, and dam-building are other impacts that are closely tied to economic development. Sand is used in making cement for construction purposes. Anyone who has visited China recently knows that the building is not going to stop any time soon... not with China's goals to urbanize its population. The dredging occurs on a 24-hour basis, disrupting fish beds and eggs in the sediment and leading to a decline in the porpoises' prey. This likely has an impact on the local fishermen as well, leading them to use increasingly extreme methods to keep their catches high for the market. For example, apparently Dongting Lake (one of the key habitats for the porpoise) is a maze of finely woven fishnets--a haven turned deathtrap for porpoises. At this lake, a few local activists--the Yueyang Finless Porpoise Protection Association--have been working to educate fisherman and even succeeded in getting the sand-dredging to stop during nighttime hours. According to them, their actions have led to a slight increase in the population of porpoises at that lake. If that is true, then education and compromises with economic interests might what we need to keep the Yangtze finless porpoise from going extinct.

A nation's waterways are critical economically. By cleaning them up and taking care of them, the governments could help to ensure economic prosperity in the long term while also benefiting people who depend on it for their livelihood. The fact that China has already lost the baiji and stands to lose another intelligent mammal serves as a warning that public health is also at risk. People are living next to those factories, drinking that water, and eating that fish. If the resources are not sufficient to maintain a population of more than 1000 finless porpoises, what does that mean for people down the road?

Scientific facts on the Yangtze river porpoise

When I tell other people about the Yangtze finless porpoise, their first reaction is nearly always: “But how does it swim?” I'm sure they're picturing something that resembles a dolphin just rolling and floating around in the water, because they are also usually laughing when they try to picture it. In fact, the Yangtze river dolphin lacks a dorsal fin, yes, but it still has everything else in place that it needs to swim. Some researchers suggest that the lack of a dorsal fin is an adaptation to their environment. It might have something to do with the relatively calmer, shallower waters that they inhabit as compared with their sea-dwelling relatives.

The Yangtze finless porpoise is actually a sub-species of finless porpoises. The other populations are found along the coasts of Japan and China. There is also a similar species that is attempting to survive in the upper reaches of the Ganges River. The freshwater sub-species survive by means similar to other porpoises and dolphins. They use echolocation to navigate underwater and feed on fish. They also live in pods or small groups and communicate with each other through clicks and squeaks. Studies on their communication habits suggest that, perhaps because of the higher sediment load of the Yangtze River, these porpoises produce clicks at higher frequencies than saltwater porpoises.

A number of population studies have been carried out over the past few decades, and none of the trends are good. One carefully conducted population survey of Yangtze finless porpoises was conducted using two boats and field observations from the upper Yangtze River by Yichang down to the lower Yangtze River by Shanghai in November and December 2006.

Zhao, W., Barlow, J., Taylor, B. L., Pitman, R. L., Wang, K., Wei, Z., Stewart, B., Turvey, S.T., Akamatsu, T., Reeves, R.R., Wang, D. (2008). Abundance and conservation status of the Yangtze finless porpoise in the Yangtze River, China. Biological Conservation, 141:3008-3018.

The greatest amount of porpoises were found in the middle reaches of the river, around Wuhan and down to Poyang Lake. The smallest, and also most separated, population was at the upper reaches by Yichang. Both Dongting Lake and Poyang Lake existed as important habitats for this animal in the past, but now the porpoises face severe threats in these places as well as throughout the rest of their range. Depending on the statistical measures used, estimates of the porpoises from older studies (late 1980s to early 1990s) tell us that populations went from between 1450 and 1650 individuals down to about 800 individuals in 2006. (These are the numbers I kept reading that made me stop and want to just hide my head under a blanket instead of continuing with the blog.)

At the Baiji Dolphinarium in Wuhan, captive breeding programs have been carried out successfully. Judging from their publications, the authors from this research station do not appear confident in the porpoise's survival prospects in its natural environment and they stress the need for more captive breeding in order to understand the reproductive behaviors of the animal. The females can breed at around six years of age. The first freshwater finless porpoise born in captivity was a male at the Baiji Dolphinarium in 2005. These researchers also stress the the need for more and better reserves. So far, the most successful and encouraging reserve is the Tian'e-Zhou Oxbow Nature Reserve, formed by the Yangtze River near Shishou and now serving as the protected home of at least thirty porpoises that have been allowed to live and breed there.

As I mentioned briefly in my previous post, the Yangtze river porpoise's protection status has been upgraded. In my next post I will discuss what this means along with what it means in terms of conservation protocol.

Good news, to be followed by science, finally

I started this blog imagining that I would write three neat articles about the Yangtze finless porpoise and then move on to a next topic. What ended up happening is that I got so depressed from reading about the low survival prospects for this animal that I couldn't even write about it.
Fortunately, as of October 28 of this year, China's Ministry of Agriculture declared the Yangtze finless porpoise "first glass protected species," putting it in the same category as the great panda. It will now get real attention and the Chinese government will be able to put in place stricter protection measures.
Thank you, The WaterHub, for the good news.
Now I can write about the science.