Abstract:
Blast fishing is an illegal fishing method that not only affects fish populations and the marine ecosystem, but also local food security and local economy. Despite its effects, blast fishing continues to persist in many coastal regions around the world, including Todos os Santos Bay (BTS - Baia de Todos os Santos) in Northeastern Brazil. This study provides the first acoustic record of underwater explosions along this region. The acoustic data were collected between 2016 and 2018, from a boat-survey platform, using a portable system consisting of an HTI-90 min hydrophone (sensitivity of about -165 dB re 1 V/μPa) connected to a TASCAM DR-40 digital recorder (combined frequency response up to 30 kHz), recording at 7 m depth. The acoustic analysis was performed using both RAVEN 1.6 and MATLAB 2021a softwares. The results revealed a distinctive underwater explosion signal detected in the BTS, indicating evidence of blast fishing activities. The acoustic characterization of blast fishing in BTS provides crucial information on its occurrence and extent of this destructive practice worldwide.
摘要:
爆炸捕捞是一种非法捕捞方法,不仅影响鱼类种群和海洋生态系统,还有地方粮食安全和地方经济。尽管有影响,爆炸捕鱼继续在世界各地的许多沿海地区持续存在,包括巴西东北部的托多斯·桑托斯湾(BTS-BaiadeTodososSantos)。这项研究提供了该地区水下爆炸的第一声记录。声学数据是在2016年至2018年之间从船舶测量平台收集的,使用由HTI-90min水听器组成的便携式系统(灵敏度约为-165dBre1V/μPa)连接到TASCAMDR-40数字记录器(组合频率响应高达30kHz),记录在7米深。使用RAVEN1.6和MATLAB2021a软件进行声学分析。结果显示,在BTS中检测到一个独特的水下爆炸信号,表明爆炸捕鱼活动的证据。BTS爆炸捕捞的声学特征为其在全球范围内的破坏性活动的发生和程度提供了重要信息。