A number of large pelagic
species are taken by fishermen trolling in the offshore waters
of Guam. Trolling involves towing lures of various kinds
with a boat through schools of surface-dwelling fish. Each
fishermen has his own idea of what kind of lure is best for what
kind of fish. Most lures resemble squids, but many successful
lures look like nothing ever seen before, and the fish seem to
bite them more out of curiosity than by mistaking it for something
it ordinarily eats. Yellowfin and skipjack tuna, wahoo (p.
119), blue marlin (p.
121), mahimahi (p.
49), barracuda (p.
125), and rainbow runner (p.
47) make up most of Guam’s trolling catch. Recent experiments
with ika-shibi fishing, a method of deep nighttime tuna handlining
using squid or atulai for bait, and small-scale longlining have
been showing promise. If these methods prove successful,
deep-dwelling yellowfin and bigeye tuna may soon make up a significant
proportion of Guam’s offshore fishing catch.
A fishing method of growing
importance on Guam is bottom-fishing, handlining for deep bottom-dwelling
snappers (pp.
53–57), groupers (p.
37), and jacks (p.
45). Bottomfish tend to live around deep pinnacles,
and the best depth for catching these fish is about 100 fathoms
(600 ft). The gear consists of a long handline with a bag
of chum (chopped fish), a series of baited hooks, and a weight
at the end. When the hooks reach the appropriate depth,
the line is jerked to release the chum, and, if the area is a
good one, the f ish soon begin to bite.
Atulai (p.
49) are also caught by offshore fishermen who fish at night
with a light and handline. The light attracts zooplankton,
and the atulai, which feed on the zooplankton, are also drawn
near the boat where they can be caught. This method works
best on moonless nights as the nightlight is then more conspicuous.
Fishermen from foreign
nations, principally Japan, Taiwan, and Korea, also fish the waters
near Guam. These countries operate skipjack pole-and-line
vessels, which target on surface-dwelling schools of skipjack
and yellowfin tuna, and longliners, which catch deep-living tunas
and marlins. Little information is available on the catches of
Taiwanese and Korean fishermen in these waters, but Japanese longliners
and pole-and-line vessels harvested more than 8 million pounds
of pelagic fish from the Fishery Conservation Zone (“200-mile
zone”) around Guam in the year 1977 alone.
The University of Guam
Marine Laboratory has been investigating the feasibility of farming
marine fishes (mariculture). Studies so far have involved
rabbitfish (p. 117)
and mullets (p. 123),but
there are many fish groups which may be potential candidates for
mariculture on Guam. It may be possible to raise small species
of fish to serve as live bait for the development of a local skipjack
pole-and-line fishery.
The great variety of
beautiful reef fishes around Guam has stimulated the popularity
of marine aquarium keeping. For those interested in taking
up this hobby, many useful books are available which describe
the setting up and maintenance of marine aquaria. Some of
the more exotic reef fishes from Guam are exported to Hawaii and
the mainland U.S. where they are in great demand by many tropical
fish hobbyists.