Abstract
African inland fisheries have been observed to sustain high sustainable catches by
harvesting a broad spectrum of species and sizes, despite their open-access nature and
overall non-selective, mostly unregulated multi-gear fisheries. We use twenty years of
multispecies data from experimental fisheries in a fished and an un-fished situation of
Lake Kariba to examine whether structural changes in the fish community have occurred.
The inshore fisheries on the Zambian side of the lake has had virtually no enforcement of
regulations, and experienced high fishing intensity with changing fishing pattern towards
increasingly smaller mesh sizes. This resulted in a higher exploitation level, higher yield
and reduced stock sizes compared to moderately fished, regulated Zimbabwean side of
the Lake, where large sections remained un-fished. Yet, the overall community and sizestructure
of the fished situation remained intact, as inferred from (1) directional trends
in species composition in the catch and in experimental surveys; (2) recruitment, length
and catch rate indicators on a community level as well as main targeted species; and
(3) changes in the overall and internal structure of the size spectrum. The Ecosystem
Approach to Fisheries calls for an optimum fishing pattern with yield levels that infer the
least structural changes on a fish community. As an example, Lake Kariba may indicate
that this could be reached by an overall unselective multi-gear fishery.
| Original language | English |
|---|---|
| Publication status | Published - 2012 |
| Event | 6th World Fisheries Congress, Sustainable Fisheries in a Changing World, Edinburgh, Scotland - Duration: 7 May 2012 → 11 May 2012 |
Conference
| Conference | 6th World Fisheries Congress, Sustainable Fisheries in a Changing World, Edinburgh, Scotland |
|---|---|
| Period | 7/05/12 → 11/05/12 |
