DFO Maritimes Biofouling Monitoring Program

Fisheries and Oceans Canada’s (DFO) National Biofouling Monitoring Program (BMP) has conducted annual field surveys to monitor the introduction, establishment, spread, species richness, and relative abundance of native and non-indigenous species (NIS) since 2006. Standardized monitoring protocols employed by DFO-Maritimes, -Gulf, and -Quebec Regions include biofouling collector plates deployed from May to October at intertidal and shallow subtidal, geo-referenced sites, including public and private docks, aquaculture lease sites, public and private marinas and yacht clubs. Initially in the Maritimes Region (2006-2017) collectors consisted of 3, 10 cm by 10cm PVC plates deployed in a vertical array and spaced approximately 40-cm apart with the shallowest plate hung at least 1 m below the surface to sample shallow subtidal and intertidal species (Sephton et al. 2011, 2017). Two replicate arrays were deployed at least 5 m apart per site. Since 2018, collector arrays were modified to enhance statistical replication, including 10 individual collectors deployed per site at 1 m depth and at least 5 m apart (as above) from May to October. The percent cover of AIS on all collectors was determined by visual examination and scored as follows; (i) ‘0’ = absent, (ii) ‘1’ = ≤25 % cover, (iii) ‘2’ = 25 to ≤50 %, (iv) ‘3’ = 50–75% , and (v) ‘4’ = &gt;75%. Average percent cover is provided for all NIS observed annually per site. Presence-absence indicates that an NIS was observed on at least one collector plate. One additional rocky intertidal species (Asian shore crab; Hemigrapsus sanguineus) was assessed via beach surveys as permitted by time and resources following its initial siting in St Mary’s Bay (Nova Scotia) in April 2020. Rapid assessment surveys conducted in the Fall of 2020 and 2021 were employed to delineate H. sanguineus’ distribution and relative abundance. Areas deemed suitable and at high risk for spread were targeted, including exposed rocky intertidal habitat in southwest regions of Nova Scotia and New Brunswick. Each rapid assessment consisted of 30-minute beach surveys per site conducted by 2 or 3 people (modified from Stephenson et al. 2011). During each survey, crabs were collected under rocks and seaweed in preferred cobble/boulder habitat (Lohrer et al. 2000). Count data was standardized for each site as the number of crabs collected per 30-min search per person.加拿大渔业与海洋部（Fisheries and Oceans Canada, DFO）的国家生物污损监测计划（National Biofouling Monitoring Program, BMP）自2006年起开展年度野外调查，以监测本土物种与非本土物种（non-indigenous species, NIS）的引入、定殖、扩散、物种丰富度及相对丰度。加拿大渔业与海洋部大西洋区、湾区及魁北克大区采用的标准化监测规程包括：于每年5月至10月，在潮间带与浅潮下带的地理标记点位布设生物污损收集板，点位涵盖公共与私人码头、水产养殖租赁场地、公共与私人游艇码头及游艇俱乐部。 2006年至2017年期间，大西洋区初始采用的收集装置为3块10 cm×10 cm的聚氯乙烯（PVC）板，以垂直阵列形式布设，板间距约40 cm，最浅的一块悬挂于水面下至少1 m处，以采集浅潮下带与潮间带物种（Sephton等，2011、2017）。每个点位布设两组重复阵列，阵列间距不小于5 m。2018年起，为提升统计重复度，收集阵列进行了优化调整：每个点位于1 m水深处布设10个独立收集装置，装置间距不小于5 m（布设规则同上），监测时段为每年5月至10月。 所有收集装置上的外来入侵物种（Alien Invasive Species, AIS）盖度通过目视检查确定，并按如下标准评分：(i) ‘0’ = 未检出；(ii) ‘1’ = 盖度≤25%；(iii) ‘2’ = 25%<盖度≤50%；(iv) ‘3’ = 50%~75%；(v) ‘4’ = >75%。各点位每年观测到的所有非本土物种的平均盖度均已给出；存在-缺失记录则代表该非本土物种至少在一块收集板上被检出。 2020年4月，亚洲滨蟹（Hemigrapsus sanguineus）在新斯科舍省圣玛丽湾首次被发现后，基于时间与资源条件，通过海滩调查对该岩相潮间带物种开展了评估。2020年与2021年秋季开展的快速评估调查用于明确该滨蟹的分布范围与相对丰度。调查优先针对适宜其生存且扩散风险较高的区域，包括新斯科舍省西南部与新不伦瑞克省的裸露岩相潮间带生境。每次快速评估由2~3名调查人员对单个点位开展30分钟的海滩调查（方法改编自Stephenson等，2011）。调查期间，在滨蟹偏好的砾石/巨砾生境（Lohrer等，2000）中的岩石与海藻下方采集螃蟹样本。各点位的计数数据均经过标准化处理，以每名调查人员每30分钟搜索采集到的螃蟹数量作为统计指标。