Population Assessment and Field Camp

One of the major objectives of the NOAA Fisheries Marine Mammal Research Program (MMRP) at PIFSC is to monitor and assess the six main Hawaiian monk seal reproductive subpopulations in the Northwestern Hawaiian Islands. To accomplish this, the MMRP sends biologists to each location for 3-6 months annually. Camps usually commence in April or June and are completed in August.

The field teams at all locations share common objectives: measure and tag all weaned seal pups; resight previously tagged seals; count each seal subpopulation by individually identifying seals with tags, naturally occurring scars or markings, and applied bleach marks; document births, deaths, serious injuries, and entanglement in marine debris; conduct necropsies on dead seals; collect seal scats (feces) for dietary information habit analysis; and collect and remove any marine debris which presents an entanglement threat to Hawaiian monk seals.

Other objectives are unique to particular subpopulations and field camps. For example, at Laysan and Lisianski Islands, longer camps allow biologists to establish the identity of parturient females (females that give birth) and to assess the incidence of male aggression against females (which usually occurs early in the reproductive season). At French Frigate Shoals, where seal pups are particularly susceptible to shark attacks, biologists conduct extensive monitoring of shark/seal interactions and tag sharks to assess how many individuals are killing pups.

Midway Atoll, once a Naval Air Facility occupied by several thousand people, is now the site of a refuge under the jurisdiction of the U.S. Fish and Wildlife Service (USFWS) Midway Atoll National Wildlife Refuge (NWR). On Midway biologists live in converted barracks or houses and have all the usual amenities such as running water, sewage, and electricity.

The other inhabited atoll is French Frigate Shoals, the site of a USFWS field station on Tern Island. It is staffed by permanent USFWS employees and volunteers. The facilities are the remnants of a U.S. Coast Guard LORAN (long-range aid to navigation) station, which was abandoned by the Coast Guard in the late 1970s. Buildings include a barracks, a generator building (currently being converted to storage and laboratory space), and a small boathouse. Tern Island includes a 3000-ft active runway, so access is either by small chartered aircraft or by vessel.

All other islands (Kure Atoll, Pearl and Hermes Reef, Lisianski Island, Laysan Island, Necker Island, and Nihoa Island) are uninhabited and are accessible only boat. Kure Atoll, the northernmost island, has a small building, a relic of a Coast Guard LORAN station, and an abandoned and unusable runway, but no electricity or running water. None of the remaining islands have any structures or facilities. All living accommodations (tents), food, water, and biological equipment must be carried ashore by the field party and must be sufficient to last the duration of the whole camp since resupply visits are rare. The NOAA Ship Oscar Elton Sette is the ship which usually helps establish and break down field camps.

Because these islands are very remote, many common insects and non-native plants ("weeds") are not present. Biologists must follow strict quarantine procedures to ensure that alien pests are not introduced. All equipment used on each island must be either brand new or previously used only on that particular island. Large gear and equipment such as tents must be frozen for at least 48 hours before being allowed on each island. The same restriction applies to personal clothing. Moreover, because insects, insect eggs, and plant seeds can be hidden in cardboard, all food items must be removed from their cardboard containers and repackaged into plastic bags. Most of the supplies and equipment are transported between the ship and the island in sealed plastic 5-gallon buckets.

Once the field camp is established, the biologists settle into routine monitoring of the seal population. Formal seal censuses are conducted approximately every 4 days. On these days, biologists will not leave camp until the census begins, lest their presence on the island perimeter affect the number of seals that might be present that day. On non-census days, biologists monitor the population by walking along the island perimeter to view tags, document any recent events such as births, weanings, or deaths and to apply temporary bleach marks to seals. For those sites that are atolls, the biologists travel among different islets using a small boat.

Field biologists identify seals by comparing new photos, field notes, and drawings with existing drawings and photos in the digital photo database, enter all data and photographs into field databases, and complete various data tables in the master field log. Personnel share all the "housekeeping" duties such as camp maintenance and repair, cooking, and dishwashing. Fresh water is used only for drinking and cooking, so seawater is used for bathing and washing clothes. Stoves and lights are propane powered. Electricity is obtained from storage batteries charged by solar panels. Small generators are available for emergency backup. Communications between camps and with Honolulu are limited to marine satellite telex (INMARSAT) and satellite phone for voice and e-mail. Voice communication via satellite phone is generally used only in urgent situations because of the high expense involved.