R
robertlo
Guest
does oyster culture have negative and positif effects to water body?
The Green Pearl Issue
Written by: Neil Anthony Sims
...So, are pearl farms bad, benign, or beneficial? Years ago, we had suggested to several individuals actively involved in environmental conservation in the South Pacific that instead of (or as well as) setting up a National Marine Park, they should set up a pearl farm. Our suggestion was ignored, or dismissed, I guess. I’ve not heard of any pearl farms in any Southeast Asian or Melanesian National Parks, but I still think it’s a stellar idea. The biological benefits are tremendous (all that wonderful vertical relief for biomass to build up, and for fish recruitment), the protection afforded coral reefs by a pearl farm’s armed guards is unimpeachable, and there is no other industry that provides such stable, lucrative employment opportunities for isolated atolls. You have probably heard all this before, but please allow me to restate the case for the defence en toto.
The benefits from pearl farming
Pearl farming is an ideal development opportunity for remote communities. It is a sustainable, lucrative industry, and in many cases it provides both direct and indirect benefits to the environment. The direct benefits are from reducing the pressure on stocks depleted by years of pearl shell fishing, and fostering the recovery of pearl oyster populations. Indirect benefits are in providing a viable, sustainable industry for rural areas and isolated atolls, and in encouraging greater stewardship of marine resources.
Pearl farming is eminently sustainable, from a stock management perspective. In almost every pearling area in the world today, farming is based on spat produced in hatcheries, or taken from artificial spat collectors. The only continuing reliance on fishing of wild stocks for farms is in northern and western Australia, where the collection of wild oysters is a tightly regulated, stable fishery.
Pearl farms can help overfished stocks recover by acting as reproductive nodes – aggregations of large, densely packed, well-tended adult oysters. The large number of fecund oysters, in close proximity to each other, results in better synchronisation of spawning, higher fertilisation rates, and far greater numbers of viable larvae, compared to the conditions of a depleted population, where oysters may be hundreds of meters, or even miles, apart. In French Polynesia and the Cook Islands, stocks formerly suffered from continual boom-and-bust fishing for the oysters, solely for the value of the pearl shell. However, over the last few decades, since the advent of large-scale farming in these atolls, spat falls and wild oyster stocks have both increased dramatically. Black Pearls, Inc. has a pending application for a pearl farm lease here in Hawaii that is largely justified by the project being a public—private partnership: a pearl farm and stock re-establishment programme rolled into one. The oysters on the farm will be the broodstock that replenish the surrounding reefs with Hawaii’s imperilled endemic oyster.
Pearl farming is labour-intensive, and provides employment for both farm workers and in spin-off secondary support industries. Pearl farming thereby relieves pressure on other marine resources, such as reef fisheries, that might otherwise be subject to unsustainable commercial exploitation.
Pearl farming also encourages island communities towards greater stewardship over their natural resources, and fosters reassertion of their traditional tenure regimes. At a pearl farm in Palawan, Philippines, where we have worked for about five years, the pearl farm areas were the only ones where there was any reasonable coral reef left. Prior to the farm’s establishment, I was told, dynamite fishing was rampant throughout the area. To this day, the reefs that lie outside of the range of the farm guards’ spotlights and AK-47s, are completely damaged. The reefs beneath the pearl farm rafts and longlines are indescribably beautiful.
Pearl oysters are filter feeders, and require no supplementary feeding. In areas of high water turbidity, the oysters may even improve water quality, by clearing suspended particulates. The animals are highly susceptible to any environmental perturbation, which is why farms are often located in remote areas. Farmers therefore are often strong advocates for marine environmental protection and management.
Pearl farm developments across the Pacific are supported by a wide range of environmental and development agencies, including the WorldFish Center in Malaysia, Sea Grant College programme in the US-affiliated Pacific, ACIAR (Australian Center for International Agricultural Research), and the Secretariat of the Pacific Community (SPC—our publisher).
We believe so strongly in the power of the pearl to protect that Black Pearls, Inc. eagerly compiled a comprehensive EIA for a pearl farm proposal by the Cook Islands government to develop pearl farming in a national park in the Cook Islands, in the remote lagoon of Suwarrow. We believe that there is no incompatibility between the protected park status and the pearl farm operation; indeed, the farm would have provided some capability to enforce the national park management plan, and would have afforded some level of protection for the fragile reef resources. We are waiting to hear of the next move in this direction by the Cooks government, or perhaps Suwarrow will be left languishing.
Green tinge to this POIB issue
Environmental consciousness grows apace. Bo Torrey’s Pearl World (The International Pearling Journal) recently focussed an entire issue on the Pew Oceans Commission report, entitled "What’s happening to our oceans". The subtext of this issue was "So you love pearls? You need to be more environmentally aware and active, or there may not be any more". Bo is to be applauded for taking such an activist stance. There is not much in the Pew report that relates directly to pearling, so rather than reprint large sections of this issue here in POIB, we suggest that, if you are interested, you write to Bo and ask him for a copy of that issue (Volume 12, No. 2). By the way, we still shamelessly lift excerpts from several other Pearl World articles for our POIB, as usual. There is simply no better source of information on what’s moving, shaking, and breaking in pearling.
The environmental impacts of pearling were recently a hot issue in New South Wales, Australia, where the government fisheries agency and private partners were proposing to expand some pilot-scale trials with the local akoya-relative (Pinctada imbricata) in Port Stephens. This project earned an initial thumbs-up from the environmental commissioner appointed to adjudicate the project proposal. It now seems, however, that the opponents have hounded the project to death.
In an attempt to provide some perspective (or perhaps just because it was an interesting bit of science), the researchers working on this project also recently published an article pointing out the powerful bio-remediative potential of pearl oysters, particularly their ability to remove heavy metals from polluted waters.
Closer to home, Black Pearls, Inc. has been working for several years on a US Department of Defense research project to validate the use of P. margaritifera as a heavy metal monitor. We publish excerpts from the report of our first stage of this work; a second stage has just been initiated.
This issue also refers to two articles on pearl oyster genetics, as they relate to our environment (see "Other publications noted", p. 39). One article from Mexico suggests that the uncontrolled plunder of the pearl oyster beds in the last century has had a significant impact on population structures of P. mazatlanica along the Pacific Coast of the Americas. The other article assesses the impact of pearl farming on the genetic variability of wild and cultured oysters in French Polynesian lagoons, and gives a "green" light.
Two other noteworthy inclusions in this issue: In the Abstracts section (p. 24), we provide a list of advance abstracts for the pearl sessions at the upcoming World Aquaculture Society meeting in Honolulu, in March 2004. Richard Fassler is billing this as the tenth anniversary of "Pearls ‘94 ". We hope to see you there.
And in the News and Views section (p. 18), we start off with a wonderful tirade from a very irate technician, berating your editor about my "negative remarks about technicians (who) won’t reveal operations techniques, and the so-called exorbitant fees that they charge". This letter was faxed in anonymously. If the author(s) had identified themselves, and asked for my response, I might have pointed out that these comments weren’t mine. I write the editorials, and the occasional tirade of my own (under my own byline), but the rest of the POIB consists of contributions from other correspondents, or excerpts from other articles published elsewhere. In this instance, the negative remarks about technicians were included in an excerpt from a story in the Cook Islands News. This article was itself paraphrasing Cook Islands pearl farmers’ comments. They said it; someone else wrote it down; we just copied it. Anyone who knows us knows that we love our seeding technicians.....