Effects Of Trace Metals, Harmful Algal Blooms, Nutrients And Hydrological Variables To Mullet (Liza Klunzingeri) In Kuwait Bay

A. H. Bu-Olayan and B. V. Thomas

POB 5969, Department of Chemistry, Kuwait University, Safat - 13060 (Kuwait).

ABSTRACT: A catastrophic ‘fish kill’ took place in Kuwait Bay between 1999 and 2000, specifically to mullet, Liza klunzingeri. Its recurrence in the consecutive years in low profile only in the Bay region and not elsewhere along the Kuwait Coast stimulated us to investigate the causative factors in five important sites of Kuwait Bay. Among various Harmful Algal Blooms (HABs), Dinophysis caudata was found predominant in the five sites of the Bay. Trace metal levels in seawater, HABs and L. klunzingeri were higher (8.11 ?g l-1, 45.14 ?g g-1and 67.81 ?g g-1, respectively) during HABs enrichment than during their absence (6.11?g l-1 40.29?g g-1 67.41?g g-1, respectively). Observations revealed high mortality of this species due to high trace metals with low nutrient levels (Phosphate, Nitrate and Silicate), and high ammonia levels during high HABs enrichment. Further, high temperature, turbidity and low dissolved oxygen were found to enhance the HABs in the Bay. These variations can be attributed to pollution from wastewater discharges, anthropogenic sources, rapid industrialization and human activities in the Bay. Furthermore, such ‘fish kills’ may not only recur in the near future but are anticipated to cause (1) direct and indirect harmful effects to fish consumers, in man and (2) economical loss from fishing industry, and hence the investigation.

KEYWORDS: Trace metals; HABs; L. klunzingeri; Kuwait Bay

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