Naturat Irensiata: Our Natural Heritage

The Division of Fish and Wildlife is updating and refining its list of species and habitats of greatest conservation concern as part of the Comprehensive Wildlife and Fish Conservation Plan for the CNMI. In general, the purpose of a conservation plan is to focus limited resources in the most effective way to protect critical species and their habitats and to maintain ecosystem services. These plans guide managers in preserving both the long-term health of our island environment and the benefits it provides to residents. The first step in creating such a plan is determining which species are most in need of protection. DFW has developed a draft list of these species and habitats, which includes birds, land animals, and marine species. Below you will see a list of all marine species now on the draft list, but for a copy of the complete list, call 322-5222. Do you have a species of fish that you love to catch? Do you think that certain land animals are becoming less common in the CNMI? Well, now is your chance to act.

The DFW requests public comments about these species or any other marine or land species that you feel should be addressed through management and conservation actions. Let us know your thoughts by email: CNMI_wildife@msn.com. Or you can send them by mail to: Comments, P.O. Box 506369, Saipan, MP 96950.Or, attend one of the following public meetings (all meetings will begin at 7 pm).

Saipan
Tuesday April 19
Garapan Elementary School

Rota
Monday April 25
Northern Marianas College

Tinian
Thursday April 28
Tinian High School

Sea Urchins and Sea Cucumbers

Over the past four weeks we have brought you articles pertaining to the Mariana fruit bat, Commonwealth birds, coconut crabs, and the green sea turtle. Today we bring you additional information pertaining to some of our marine species.

Our costal lagoons are home to hundreds of fish and invertebrate species, living in more than 30 different unique habitats. Sea urchins and sea cucumbers are just a few of the many organisms that inhabit our coastal waters. These species belong to the Echinoderm family, which also includes sea stars. Echinoderms feed on a variety of live and dead plankton, algae, and micro-invertebrates in the water and lagoon floor. They essentially act as biological water filterers.

The collector sea urchin (Tripneustes gratilla), the surf redfish sea cucumber (Actinopyga mauritiana), and the black teatfish sea cucumber (Holothuria whitmaei) are echinoderms inhabiting our coastal lagoons.

The collector urchin is distinguished from other urchins by its short spines and the bits of sea grass or algae collected on the surface of its body. The reason for this collecting behavior is unknown, although scientists believe that it may be for protection from sunlight or camouflage against predators. These sea urchins are favored for their “ono” (eggs) and are harvested by many Pacific Islanders and other ethnic groups living in the Commonwealth.

The collector sea urchin is found within sandy sea grass beds or near coral encrusted rocks. It was once common in the Saipan Lagoon, but the populations have declined during recent decades. Some fishermen have stated that as late as the 1970’s “basketfuls” of these urchins were collected for their eggs. The decline of this sea urchin population coincided with Saipan’s significant population growth of the 1980s and 1990s, as well as commercial sea cucumber harvesting that occurred during the mid-1990s. Some reports suggest that the collector urchin may now be rare or extinct within Saipan’s waters.

Sea cucumbers typically live for five to 10 years and primarily inhabit the sandy bottoms of our lagoons. Unlike sea urchins and sea stars, sea cucumbers do not have an exoskeleton for protection. The surf redfish and black teatfish sea cucumbers were overharvested as a food source in 1996 and 1997, and are now protected by local fishing regulations. A CNMI-wide moratorium has been imposed on collecting sea cucumbers, so that their populations can be sustained. Two sea cucumber reserves also have been established, in Lau Lau Bay and at Forbidden Island. (Information contributions from CRMO’s Kathy Yuknavage and DFW files.) (Greg Schroer)

(Greg Schroer is a consulting scientist and planner at the Division of Fish and Wildlife, Department of Lands and Natural Resources.)