Moratorium on topshell harvesting

There are a variety of seashells that are used for food here in the Commonwealth of the Northern Mariana Islands. One of these seashells is a marine snail called Trochus niloticus, or topshell. Known in Chamorro as alileng tulumpo, the topshell can be found in fringing reefs and reef flats, and grows to about 50-150 mm in size. In other parts of Micronesia the meat of the top shell is commercially harvested for food, and its pearly shell is used for buttons and jewelry. A moratorium or ban on fishing the topshell has been in effect since 1983 to protect it from overfishing and exploitation. The harvesting of any part of the top shell dead or alive is illegal.

There is evidence of illegal top shell harvesting around Pau Pau Beach. Numerous broken pieces of topshell lie scattered around a number of boulders in the reef flats. Poachers are most likely collecting the top shell meat, and discarding the heavy shells to lighten their load, and rid themselves of the easily identifiable evidence. It cannot be determined if the meat has been sold commercially. If caught, violators are subject to penalty fines from $100 to $2500, and may also have their gear and equipment confiscated and not returned.

Many residents believe that the topshell is native to the CNMI since it has a local name. The Japanese South Seas Government actually introduced the topshell to Saipan in March 1938 with the hope of establishing a population as a food source. Successive introductions from that population were made to Rota, Tinian, Guam and Agrihan in the early 1950s. According to Michael S. Trianni, Department of Fish and Wildlife marine biologist, during the early Japanese mandate years, the topshell was not heavily harvested. There weren’t any harvest at all during the war years from 1942 to 1946. During the Trust Territories of the Pacific Islands period harvesting was restricted to any 14-day period during the months of May, June, or July, with a shell size restriction of three inches in basal diameter. Unrestricted harvest occurred during the establishment of the CNMI in 1976, and lasted until 1981 when the 2nd CNMI Legislature created DFW, giving them management authority under CNMI’s Department of Lands and Natural Resources to regulate topshell harvest. In 1981, DFW designated a mile-long stretch at Lighthouse Reef in Garapan and Tanke Beach in the eastern side of Saipan as a Trochus reserve, where harvesting was banned. Authority was given to the Secretary of DLNR to establish a harvesting moratorium, authority to open topshell harvest season under permit, and set the minimum harvest size allowable at three inches basal diameter.

In 1993, DFW, with help from the South Pacific Commission, conducted a study on Rota, Tinian, and Saipan, and determined that the population density of the topshell was too low to sustain a commercial or recreational/subsistence fishery. From this survey, it was suggested that initial topshell harvest should only be limited to no more than five tons of dry shell. This report also concluded that Tanke Beach did not have the topshell population to warrant sanctuary designation.

In accordance with the 1993 recommendations of the DFW and SPC topshell study, open season was declared from October to November of 1996. Due to poor oceanographic conditions, the open season was extended until December. Two companies were awarded harvesting permits, one of which also had an exporting permit. A shipment of Trochus shell was exported to Hong Kong from the CNMI in December 1996 weighing 3.9 tons and valued at $15,890. This was the last topshell open harvest season declared, and since then, DFW has extended an indefinite CNMI-wide moratorium on harvesting to protect the topshell population.

The top shell has a role in the reef’s ecosystem. It is important to be aware that overharvesting of a particular species for seafood or commercial use poses a serious threat to the health of the coral reef because it can lead to numerous environmental changes. When an important component of an ecosystem is removed, it can lead to a domino effect of degradation that is not often seen until the situation is serious. Add to this other existing environmental problems, the negative impact starts affecting other areas such as the health and marketability of a reef, eventually affecting recreation and tourism. Our reefs are our future. So please, report any illegal activities to DFW at 664-6001. (John Dax Moreno)

(John Dax Moreno is the CRMO’s Outreach and Education Coordinator.)