Poster abstracts and manuscripts from the Third International ...

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limits during the Soviet Union era. Latvian sea waters and
shores are therefore a perfect place for wildlife, recreation and
tourism. Other items in our poster include:
1) General information about the activities of the nongovernment
organizations (NGOIs) connected with marine debris
problems (namely, Coalition Clean Baltic Riga Branch,
Environmental Protection Club of Latvia and Keep Latvia Tidy
Foundation);
2) Geographical peculiarities and other characteristics of the
Gulf of Rigas;
3) Main sources of marine debris in Latvian waters;
4) Practical work and results of the NGO network in Latvia.
Hall, Martin, Marco Garcia, Alejandro Pares-Sierra, and
Pablo Arenas
The Use of a Drift Model to Simulate Trajectories of Floating
Objects and Marine Debris Entering the Coastal Areas of the
Eastern Pacific Ocean
Inter-American Tropical Tuna Commission, San Diego, California,
USA
A 1.5 reduced-gravity, non-linear model was used to obtain the
underlying ocean currents of the Equatorial Pacific Ocean. the
model was forced using realistic values of wind speed and
direction obtained from the Comprehensive Ocean-Atmospheric Data
Set (COADS). The model equations were integrated from 1971 to
1987 to obtain monthly matrices of current vectors and thickness
of the upper layer. These matrices were the input of a
Lagrangian simulation model used to predict and analyze the
trajectories of floating objects entering the eastern Pacific
Ocean through five selected locations near the mouths of major
rivers of the region.
The aspects studied for each location included (1) direction,
velocity and other characteristics of the trajectories of objects
entering the location's vicinity; (2) the influence of the origin
of the object on its final destination; (3) seasonal variation
(especially in relations to precipitation patterns) and annual
variation (with emphasis on the impact of El Nino events) in the
trajectories of objects with a common origin.
The main conclusions are that:
1) Through either cyclic current patterns or oscillating northsouth
movements, most objects are retained relatively close to
their source for considerable periods;
2) Practically all the transport offshore occurs along l0 o N
corridor;
3) El Nino events alter the patterns substantially, increasing
the velocity of the offshore movements of the objects, but always
along the l0 o N corridor.
There are many other potential uses for the drift trajectories,
among them, studies of biological, geographic and chemical cycles
involving the floating objects, distribution of marine debris,