4.3. Management implications
Managers should evaluate the importance of using varied sampling
methods (visual censuses and gillnets) during at least two different
periods (dry-turbid water and rainy-clear water) to accurately assess
the fishery resources associated with artificial reefs in the north coast of
Rio de Janeiro. Further, although fish can be influenced by artificial reefs
to a maximum distance of 100 m, the responses are species-specific,
with a sharp decrease in the total abundance and richness and the
abundance of most species at distances of 50 m or less to the reefs.
Therefore, reef setsmust be deployed with a spatial configuration so that
they do not exceed 50 m of distance gap, to enhance their usefulness for
conservation or fishery purposes. Also, if artificial reefs will be primarily
used for fishery purposes and managers prioritize reef sets of small-size
(b5 m2
) in a scattered spatial configuration (25–50 m apart), the
structures must be spread out, to allow the local inshore fishermen to
maximize their catch by fishing as close as possible to the reefs. Finally,
further effort should be employed to investigate how South Atlantic fish
react to reef distance within a fine scale approach (from few centimeters
up to 50 m) and whether the size of artificial reefs could influence such
responses.