Marine Resources Assessment for the Marianas Operating ... - SPREP

AUGUST 2005 FINAL REPORT
4.3 FISHERIES RESOURCES
The fishery resources within the Marianas MRA study area are diverse. The diverse number of species
found and fished, coupled with the diverse geography, cultural practices, and economy contribute to the
difficulty of defining fisheries (Carpenter 1998). The fisheries have been in transition since WWII. While
many traditional fishing techniques are still employed on the islands, technology has made recently
introduced methods much more efficient.
4.3.1 Introduction
The study area is in the Indo-West Pacific region – a tropical zone from east Africa across the Indian
Ocean and out into the Pacific. Zoogeographers consider this the richest area in the world in terms of fish
species (Amesbury and Myers 2001); 1,106 species of fish have been identified in the waters in and
around the study area (Myers and Donaldson 2003). See Chapter 2 for detailed descriptions of the
oceanographic and biological environment of the study area.
Commercial and recreational fishing endeavors rely on the ability to anticipate the occurrence of target
species at a given place and time. The distribution and abundance of fishery species depends greatly on
the physical and biological factors associated with the individual species such as salinity, temperature,
dissolved oxygen, food/prey availability, habitat quality, reproductive/life cycles, seasonal movements,
population dynamics, and recruitment success, among others (Helfman et al. 1999). The affinity of target
species for particular habitats, the physiological tolerance to environmental factors (e.g., salinity,
temperature, and dissolved oxygen levels), and the availability of food items are the primary factors
influencing the spatial distributions of species. Life history stages and movements, along with seasonal
environmental changes (e.g., salinity and temperature), are the primary factors that influence seasonal
distribution (Helfman et al. 1999).
Successful fishermen are able to “read the signs” and make educated guesses about where and when to
fish. Recent technologies such as sonar, radar, and GPS systems as well as detailed bottom topography
maps and real-time meteorological/hydrological information assist in the search for fishery species.
Variations in distribution and abundance of fishery species are influenced by both natural and
anthropogenic activities (Waite et al. 1994).
4.3.1.1 Fisheries Problems
Although natural patterns of variation are expected in marine fishery stocks, human activities are known
to have definite effects on fish distributions and abundances. Over the past two centuries, and especially
within the past 50 years, the overall intensity of fishery effort (commercial and recreational) has increased.
High demand for fishery products has led to increased fishing activity and resulted in the depletion of
certain species stocks (Waite et al. 1994; Parker and Dixon 1998). While improvements in fishing gear
and methods continue, overall catch rates in relation to effort expended are decreasing. Fishery declines
are directly and indirectly attributed to several factors which include habitat loss, physical habitat damage,
natural events and cycles, fishing pressure, stream flow alteration, and degradation of water quality.
Overfishing is considered one of the main causes for declining catch rates (Waite et al. 1994). As fishery
landings diminish, species once targeted as commercially desirable have changed to include those
species that are less attractive but still available in harvestable quantities. Smaller fish, as well as those
species once discarded as bycatch, are now being targeted for commercial sales (Pauly et al. 1998).
4.3.1.2 Fisheries Management
Wise management has become crucial in protecting fishery industries and maintaining fishery resources
in a harvestable condition. At the federal level, laws, executive orders, proclamations, and regulations
have been created to aid in the conservation of fishery resources. One of the mandates of the SFA was
the creation of a number of interstate management agencies, called fishery management councils
(FMCs), to oversee the condition of fishery stocks in the federal waters of the EEZ (3 to 200 NM from
shore). The FMCs use FMPs to set forth management objectives for specific fishery resources and
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