Department of Anthropology, San Diego State University, San Diego, CA 92182-6040, USA.
Program in Human Ecology and Archaeobiology, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA.
Sci Adv. 2017 Feb 1;3(2):e1601759. doi: 10.1126/sciadv.1601759. eCollection 2017 Feb.
The intensive commercial exploitation of California sheephead () has become a complex, multimillion-dollar industry. The fishery is of concern because of high harvest levels and potential indirect impacts of sheephead removals on the structure and function of kelp forest ecosystems. California sheephead are protogynous hermaphrodites that, as predators of sea urchins and other invertebrates, are critical components of kelp forest ecosystems in the northeast Pacific. Overfishing can trigger trophic cascades and widespread ecological dysfunction when other urchin predators are also lost from the system. Little is known about the ecology and abundance of sheephead before commercial exploitation. Lack of a historical perspective creates a gap for evaluating fisheries management measures and marine reserves that seek to rebuild sheephead populations to historical baseline conditions. We use population abundance and size structure data from the zooarchaeological record, in concert with isotopic data, to evaluate the long-term health and viability of sheephead fisheries in southern California. Our results indicate that the importance of sheephead to the diet of native Chumash people varied spatially across the Channel Islands, reflecting modern biogeographic patterns. Comparing ancient (~10,000 calibrated years before the present to 1825 CE) and modern samples, we observed variability and significant declines in the relative abundance of sheephead, reductions in size frequency distributions, and shifts in the dietary niche between ancient and modern collections. These results highlight how size-selective fishing can alter the ecological role of key predators and how zooarchaeological data can inform fisheries management by establishing historical baselines that aid future conservation.
加利福尼亚羊头鱼（）的集约化商业开发已成为一个复杂的、价值数百万美元的产业。该渔业令人关注，原因是捕捞量高，以及羊头鱼的移除对巨藻林生态系统的结构和功能可能产生的间接影响。加利福尼亚羊头鱼是雌雄同体的雌雄同体动物，作为海胆和其他无脊椎动物的捕食者，是东北太平洋巨藻林生态系统的关键组成部分。过度捕捞会引发营养级联和广泛的生态功能障碍，当系统中其他海胆捕食者也消失时。在商业开发之前，人们对羊头鱼的生态学和丰度知之甚少。缺乏历史视角会对评估渔业管理措施和海洋保护区造成差距，这些措施旨在将羊头鱼种群重建到历史基线条件。我们利用动物园考古记录中的种群丰度和大小结构数据，并结合同位素数据，来评估南加利福尼亚羊头鱼渔业的长期健康和生存能力。我们的研究结果表明，羊头鱼在查莫罗原住民饮食中的重要性在海峡群岛各地存在空间差异，反映了现代生物地理模式。通过比较古代（距现在 10000 年到公元 1825 年）和现代样本，我们观察到羊头鱼的相对丰度存在变化且显著下降，大小频率分布减少，以及古代和现代收集物之间的饮食生态位发生变化。这些结果强调了如何通过选择性捕捞改变关键捕食者的生态作用，以及动物园考古数据如何通过建立有助于未来保护的历史基线来为渔业管理提供信息。
