Variation in the size and abundance of the dictyocerid sponge, Coscinoderma matthewsi, at different spatial scales in central and eastern Torres Strait, Australia (MTSRF Project 1.3.2)

Abundance and size of the sponge Coscinoderma matthewsi was surveyed at 5 island groups in November 2006: Ugar (Stephen Island) and Erub (Darnley Island) in eastern Torres Strait; and Masig (Yorke Island), Poruma (Coconut Island) and Warraber (Sue Island) in central Torres Strait. These island groups are on average, 66 km apart.Surveys were carried out at 7 or 8 randomly selected locations in each island group with each location at least 2 km apart, averaging 8 km. Each location was divided into 2 sites, approximately 200 m apart. At each site, three 30 x 1 m strip transects, separated by at least 20 m in depths between 7-12 m were quantitatively surveyed for Coscinoderma matthewsi. The greatest dimension of every Coscinoderma matthewsi was measured with a ruler to examine size frequency distribution patterns. For any diseased sponge, the percent of infected or necrotic pinacoderm was noted. Environmental factors were also recorded: angle of the reef slope and percentage benthic cover of rock, rubble and sand. This research was undertaken to:1. assess the abundance and size of a commercial bath sponge species, Coscinoderma matthewsi, at different spatial scales in Torres Strait. 2. identify elements of environmental risk (evidence of disease, sedimentation, invasives).

2006年11月，研究人员针对托雷斯海峡（Torres Strait）5个岛群海域的马修斯盘海绵（Coscinoderma matthewsi）的种群丰度与个体大小开展了系统性调查：其中托雷斯海峡东部岛群包含乌加岛（斯蒂芬岛，Ugar (Stephen Island)）与埃鲁布岛（达恩利岛，Erub (Darnley Island)），中部岛群包含马西格岛（约克岛，Masig (Yorke Island)）、波鲁马岛（椰子岛，Poruma (Coconut Island)）与瓦拉伯岛（休岛，Warraber (Sue Island)）。上述岛群的平均间距为66千米。

每个岛群选取7至8个随机点位开展调查，各点位间最小间距为2千米，平均间距约8千米。每个点位被划分为2个样地，二者间距约200米。在每个样地内，设置3条30×1米的条带样带（strip transect），样带间最小间距为20米，调查水深控制在7至12米之间，对马修斯盘海绵开展定量调查。

使用直尺测量每只马修斯盘海绵的最大个体尺寸，以分析其大小频率分布模式。针对染病海绵个体，需记录其受感染或坏死的海绵皮层（pinacoderm）占比。同时记录相关环境因子数据：礁坡倾角，以及岩石、碎石与沙质的底栖覆盖百分比。

本研究旨在达成以下两项研究目标：
1. 探究托雷斯海峡不同空间尺度下商用洗浴海绵物种马修斯盘海绵的种群丰度与个体大小特征；
2. 识别该海域的环境风险因子，包括病害迹象、沉积作用与外来入侵物种。