SOME OBSERVATIONS ON THE MASS MORTALITY OF FISH ‎AT ORMARA (EAST BAY), BALOCHISTAN IN OCTOBER 2016‎
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Keywords

Mass mortality‎
Noctiluca scintillans
Ormara (East Bay)
Oxygen

How to Cite

Moazzam, M. (2020). SOME OBSERVATIONS ON THE MASS MORTALITY OF FISH ‎AT ORMARA (EAST BAY), BALOCHISTAN IN OCTOBER 2016‎. Pakistan Journal of Marine Sciences, 29(2), 83–98. Retrieved from http://pakjmsuok.com/index.php/pjms/article/view/66

Abstract

Mass mortality of fish and shellfish species was recorded from Ormara (East Bay) in ‎October 2016. Initially a few dead fishes were observed to be floating in the open sea in ‎the East Bay area. With the passage of time, mass mortality was observed on the south-‎western part of the East Bay and heaps of fish were found floating in the area. This ‎event of mass mortality was only confined to the Oramara (East Bay) and not spread to ‎other parts of Oramara coast. In order to determine the dynamic of the fish mortality ‎and its spread in the area, sampling of the water of the area was collected on regular ‎intervals. It was observed that Noctiluca scintillans (Macartney) Kofoid & Swezy, 1921 ‎was present in extremely large numbers (highest recorded concentration 13 cells/ml) ‎which led to depletion of oxygen in the area resulting in mortality of large number of ‎fishes. In this fish kill demersal (bottom dwelling) as well as pelagic species (surface ‎dwelling) were found dead in the area in large numbers. Groupers (Epinephelus spp.), ‎Chinese pomfrets (Pampus chinensis), mullets, shrimp (Penaeus spp.) and crabs ‎‎(Portunus spp.) were dominated in the dead fishes and shellfishes. Oxygen depletion was ‎observed to confine to south-western part of the Ormara Bay where highest number of ‎dead fishes were observed. The phenomenon of mortality of fishes continued for 8 days ‎whereas normal condition started prevailing in 15 days and no mortality was observed ‎after 20 days since the start of the mortality phenomenon.‎

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Copyright (c) 2020 Muhammad Moazzam