Studies on the Diversity and impact of Macro Biofouling Organisms in Brackish Water Finfish Cage
Studies on the Diversity and impact of Macro Biofouling Organisms in Brackish Water Finfish Cage
Date
2020
Authors
Sunithakumari, K.
Joseph, Shoji
Ajithkumar, P. B.
Smina, M. S.
Priya, N. P.
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Fisheries Technologists (India)
Abstract
Biofouling refers to accumulation of organisms on
submerged surfaces. In case of open water cage
culture, fouling organisms attached to cage nets
block water flow and reduces waste removal
resulting in increased stress levels on stocked fishes
and reduces the rate of intake of feed and growth.
It also increases weight of the nets leading to its
damage. The quantity and diversity of biofouling
organisms and their effects on the growth and
survival of stocked fishes were studied. The study
was conducted at Moothakunnam, Ernakulam, Kerala.
In the present investigation the data is of one culture
period (10 months February - November 2017). The
water quality parameters observed are: temperature
(24.1°C to 31.7°C), Ph (6.81-7.87), salinity (0-29),
light penetration (31.8 cm to 162.475 cm), DO (4.94-
10.528 mg L-1), nitrate (0.016-4.521 mg L-1), nitrite
(0 to 0.954 mg L-1), orthophosphate (0.011-0.771
mg L-1) and ammonia (0 to 0.031 mg L-1). Biofouling
was found initiated with filamentous algae followed
by molluscs dominated by modiolus and other
invertebrate organisms. Majority of the fouling
organisms observed were molluscs and filamentous
algae. Biofouling was highest in areas near the water
surface and found reduced with depth. Almost
44.44% of the total net area was affected by
biofouling. The total weight of the attachment with
net was 3354.88 kg. Macrobiofoulers itself shared a
total weight of 658.56 kg and modiolus (90.53%)
alone contributed 588.8 kg. Apart from these
associated animals like Arthropods, Annelids etc.
were also found. Infestation was found increased
with salinity and peaked during April-May (29 psu).
Description
Keywords
Biofouling, macrobiofoulers, cage farming