Environmental Monitoring Around an Offshore Fish Farm with Copper Alloy Mesh Pens in the Northern Aegean Sea

Yesim Buyukates

doi:10.11648/j.ajep.20170602.13

Abstract

In the present study, environmental monitoring was undertaken around an offshore fish farm with copper alloy mesh pens located in the Northern Aegean Sea. From the water velocity results obtained at the farm site, located in the Strait of Canakkale (formerly the Dardanelles) it was recorded that the horizontal water velocity reached 36cms-1 at select times. The average water velocity was found to be 22cms-1. Water quality measurements were made over an 11 months period between September 2011 and July 2012. Other than occasional wind drawn mixing events, the two different water masses can be clearly indicated depending on the temperature and salinity values recorded throughout the study period in the Strait of Canakkale. Inorganic nutrient concentrations such as NO-2+NO-3, NH4, PO4, TP and SiO2, changed from low to moderate through most of the sampling period. The data for TSS varied among sampling depths between 0.06 and 10.40 mgL-1, being below the typical seawater quality measurement threshold of 30 mgL-1 pronounced by Water Pollution Control Regulations. Chlorophyll-a concentration, ranged between 0.143-2.633μgL-1, 0.055-1.519 μgL-1, and 0.110-2.288 μgL-1, at the surface, 15m, and 30m, respectively. It has been observed that starting from March 2012, especially in Stations 2 and 3, the phytoplankton abundance controlled the TSS, rather than terrestrial sources.

Highlights

Organic matter growth on marine systems is one of the challenges for the cage aquaculture industry
The plots only present the top 11 meters of the water column as the net pens only have a draft of 5 meters, and a significant pycnocline was found at a depth of approximately 13 meters
The results indicate that the horizontal water velocity reached 36 cms-1 at select times (Figure3)

Summary

Introduction

Organic matter growth on marine systems is one of the challenges for the cage aquaculture industry. Any new production method or material for the reduction of biofouling on cage systems might bring important benefits in terms of better growth performance of fish by better feed intake, reduced stress conditions and less labor costs due to net changes or cleaning [1]. Copper alloys can be found as wire mesh materials that can be used in cage nets instead of polymer nettings. Copper alloy mesh has been reported as a biofouling resistant material for fish culture in the Mediterranean, with improved fish health under better sanitary conditions in a cleaner cage environment [1]. Copper alloy meshes demonstrated improved economic benefits when compared to traditional nylon nettings for the Atlantic salmon aquaculture in Chile [3].

Objectives

Methods

Results

Conclusion