Intertidal rack-and-bag oyster farms have limited interaction with horseshoe crab activity in New Jersey, USA
Intertidal rack-and-bag oyster farms have limited interaction with horseshoe crab activity in New Jersey, USA
复制标题
美国新泽西州潮间带架袋式牡蛎养殖场与鲎活动的互动有限
DOI：
10.3354/aei00227
复制
发表时间：
2017
影响因子：
2.2
通讯作者：
L. Calvo
中科院分区：
文献类型：
--
作者：
D. Munroe;David Bushek;P. Woodruff;L. Calvo
人们对马蹄蟹（Limulus polyphemus）穿越潮间带的架子和袋子牡蛎养殖场的能力以及养殖场如何改变滨鸟觅食活动的能力表示担忧。在2016年马蹄蟹产卵季节，在特拉华州湾（新泽西，美国）进行的实验评估了螃蟹在牡蛎养殖场之间移动和进入向陆地筑巢的能力，并调查了许多滨鸟赖以为生的脱落卵的分布。实验包括测试（1）牡蛎架对螃蟹通道的损害，（2）成对农场/对照样带之间螃蟹丰度的差异，（3）农场是否影响螃蟹在筑巢海滩上的搁浅率，以及（4）评估农场和非农场地区之间沿着沿着残骸区的脱落卵的空间分布。所有螃蟹，无论大小，都从≥10 cm高的架子下通过，表明30.5 cm的规定架子高度足以允许螃蟹在架子下移动。农场/控制人口普查观察到853蟹总数，没有证据表明养殖和控制样带之间的不同螃蟹数量。853只螃蟹中只有2只（<0.5%）被农机具挡住，与邻近的无农场地区相比，更多的螃蟹出现在农场近岸的筑巢海滩上。螃蟹翻转（搁浅）的比例在退潮筑巢栖息地内是恒定的，无论农场的存在。残骸区的脱落卵在调查区域的中心最常见，而不是集中在农场附近，这表明在2016年，滨鸟觅食的机会与农场位置不一致。
Concern has been raised about the ability of horseshoe crabs Limulus polyphemus to traverse intertidal rack-and-bag oyster farms, and how farms may change shorebird foraging activity. During the 2016 horseshoe crab spawning season, experiments conducted in Delaware Bay (New Jersey, USA) assessed the ability of crabs to move among oyster farms and access landward nesting grounds, and surveyed the distribution of dislodged eggs upon which many shorebirds feed. Experiments included testing (1) for impairment of crab passage by oyster racks, (2) for differences in crab abundance among paired farm/control transects, (3) whether farms affect crab stranding rates on nesting beaches, and (4) assessing the spatial distribution of dislodged eggs along the wrack zone among farm and non-farm areas. All crabs, regardless of size, passed beneath racks ≥10 cm tall, indicating that the regulated rack height of 30.5 cm is abundantly precautious to allow crab movement beneath racks. Farm/control census observed 853 crabs in total, with no evidence of differing crab numbers among farmed and control transects. Only 2 of 853 (<0.5%) crabs were obstructed by farm gear, and more crabs were present on nesting beaches inshore of farms compared to adjacent farm-free areas. The proportion of crabs flipped (stranded) at low tide within nesting habitats was constant regardless of farm presence. Dislodged eggs in the wrack zone were observed most frequently in the center of the survey area, and were not concentrated near farms, suggesting that in 2016, shorebird foraging opportunities were not coincident with farm locations.