2009-2016 Loxton et al., Distribution of the invasive bryozoan Schizoporella japonica in Great Britain and Ireland and a review of its European distribution

The bryozoan Schizoporella japonica Ortmann (1890) was first recorded in European waters in 2010 and has since been reported from further locations in Great Britain (GB) and Norway. This dataset provides a new earliest European record for the species from 2009. The presence records of Schizoporella japonica at 28 sites in Europe are reported only, out of the 231 sites surveyed through rapid assesment surveys. This species is typically associated with human activity, including commercial and recreational vessels, aquaculture equipment, and both wave and tidal energy devices. It has also been observed in the natural environment, fouling rocks and boulders. The species has an extensive but widely discontinuous distribution in GB and Ireland. Although found frequently in marinas and harbours in Scotland, it inhabits only a few sites in England, Wales and Ireland, interspersed with wide gaps that are well documented as genuine absences. This appears to be a rare example of a southward-spreading invasion in GB and Ireland. The species has been reported from the Isle of Man and Norway but has not been found in France or Portugal. In the future we expect S. japonica to spread into suitable sections of the English, Welsh and Irish coasts, and further within Europe. The species’ capability for long-distance saltatory spread and potential for negative impact on native ecosystems and economic activity suggests that S. japonica should now be considered invasive in GB and Ireland. As such, it is recommended that biosecurity procedures alongside effective surveillance and monitoring should be prioritised for regions outside the species’ current distribution.

日本裂口藻（Schizoporella japonica Ortmann, 1890）首次在欧洲水域被记录于2010年，此后在英国（GB）和挪威的更多地点均有报道。本数据集提供了该物种2009年的首次欧洲记录。在欧洲的28个地点报告了日本裂口藻的分布记录，这些记录仅来自通过快速评估调查的231个地点中的一部分。该物种通常与人类活动相关联，包括商业和休闲船只、水产养殖设备以及波浪和潮汐能源设备。此外，该物种还曾在自然环境中观察到，附着在岩石和巨石上。在日本和爱尔兰，该物种分布广泛但连续性较差。尽管在苏格兰的船坞和港口中频繁发现，但在英格兰、威尔士和爱尔兰仅栖息于少数几个地点，这些地点之间分布着广泛的间隙，这些间隙已被充分记录为真实的缺失。这似乎是英国和爱尔兰向南扩张入侵的罕见例子。该物种在马恩岛和挪威有报道，但尚未在法国或葡萄牙发现。未来，我们预计日本裂口藻将扩散至英格兰、威尔士和爱尔兰的海岸适宜区域，并在欧洲进一步扩散。鉴于该物种具有长距离跳跃性传播的能力以及对原生生态系统和经济活动可能产生的负面影响，建议将日本裂口藻在英国和爱尔兰视为入侵物种。因此，建议对物种现有分布范围以外的地区优先实施生物安全程序，并加强有效的监视和监测。