Habitat use and early winter movements by juvenile Atlantic cod in a coastal area of Newfoundland
Habitat use and early winter movements by juvenile Atlantic cod in a coastal area of Newfoundland
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纽芬兰沿海地区幼年大西洋鳕鱼的栖息地利用和初冬活动
DOI：
10.1111/j.1095-8649.2004.00331.x
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发表时间：
2004
影响因子：
2
通讯作者：
R. Mckinley
中科院分区：
文献类型：
--
作者：
D. Côté;S. Moulton;P. Frampton;D. Scruton;R. Mckinley
1999年10月24日至2000年1月22日，利用声波遥测技术对纽芬兰纽曼湾2 ~ 3岁大西洋鳕鱼幼鱼的活动和景观尺度生境利用进行了监测。研究了基底、等深地形和深度利用，以确定在缺乏选择性（生境利用与生境可利用成比例）的情况下，是否与预期的格局不同。在冬季迁徙之前，大多数大西洋鳕鱼保持着较小的家园范围（0.5-33.4公顷，中位数= 2.1公顷），尽管少数个体移动的范围更广。总长度（L T）与家距大小没有关系。在内纽曼湾，大西洋鳕鱼占据的深度超过了预期的10-29米，而0-9米和40-59米的深度未被充分利用。深度和LT之间没有明显的关系。考虑到这些栖息地的可用性，中（5-10%）或高（10 -10%）水深起伏和巨石或海带栖息地的使用明显超过预期。尽管许多大西洋鳕鱼在某种程度上利用了沙底地区，但鉴于可用性，沙子和鳗草的底质未得到充分利用。被研究的个体对栖息地使用的灵活性表明，相对于年轻的同种个体，捕食风险降低。在11月中旬，随着温跃层的消失，它们开始向纽曼湾以外更深的水域进行冬季迁徙，一直持续到12月27日。大约30%的监测个体没有迁移，并在冬季保持其家园范围。洄游组和留居组间的L T值无显著差异，但洄游组的L T值显著高于留居组。这一发现支持了一种理论，即饲养历史在决定进行迁移中起着重要作用。
Acoustic telemetry was used to monitor the movements and landscape scale habitat use of age 2-3 year juvenile Atlantic cod Gadus morhua in Newman Sound, a coastal fjord of Newfoundland, during late autumn and early winter (24 October 1999 to 22 January 2000). Substratum, bathymetric relief and depth use were studied to determine if it differed from the pattern expected given an absence of selectivity (habitat use proportional to habitat availability). Prior to winter migrations, most Atlantic cod maintained small home ranges (0.5-33.4 ha, median = 2.1 ha) although a few individuals moved more widely. No relationship between total length (L T ) and home range size was detected. In Inner Newman Sound, Atlantic cod occupied depths of 10-29m more than expected given availability, while depths of 0-9 and 40-59 m were underutilized. No significant relationship between depth and LT was detected. Areas of medium (5-10%) or high (>10%) bathymetric relief and boulder or kelp habitats were used significantly more than expected given the availability of these habitats. Sand and eelgrass substrata were underutilized given availability, although many Atlantic cod used sandy-bottomed areas to some degree. Flexibility in habitat use by the individuals that were studied suggested reduced predation risk relative to younger conspecifics. Winter migrations to deeper water beyond Newman Sound began in mid-November, coinciding with the disappearance of the thermocline, and continued until 27 December. Approximately 30% of monitored individuals did not migrate and maintained their home ranges into the winter season. No significant differences in L T between migrating and resident groups were detected, however, the condition of migrating fish was significantly higher than in resident fish. This finding supports the theory that feeding history plays a role in the decision to undertake migration.