My research project aimed to assess the presence of non-indigenous invertebrate species in BGTW, in particular those being introduced via hull fouling on recreational vessels. Species introduced outside of their native range can become invasive and cause economic, environmental and health issues. The impact of such invasions has led to them being considered as one of the main threats to the marine environment and its diversity. One of the main motivating factors for the project was the lack of data on non-indigenous species in British Gibraltar Territorial Waters (BGTW). The study site, Mid Harbour Small Boat Marina (MHSBM) was chosen for the baseline study. Acquiring baseline data can allow for effective monitoring of the benthic ecosystem, pin-pointing at risk areas and species of interest. The approach to the data collection combined multiple aspects, physical samples were taken from the floating pontoons at the marina to allow for laboratory identification, video and imagery was obtained to highlight the necessity for different methodologies, a level of fouling ranking was given to the vessels present on the day of sampling to gain a further understanding of the complexity of the habitat found in the marina and finally, a questionnaire was distributed to boat owners to gain a valuable insight into travel patterns as well as perceptions and knowledge.

The project not only revealed the presence of non-native species including  the shrimp, Caprella scaura and the spaghetti bryozoan, Amathia verticillata but also other environmental issues such as marine pollution due to the presence of plastic in the marina and the use of toxic coatings for antifouling. To communicate the results and mitigate further introductions and the efficient co-management of issues, a prototype of an infographic was produced, which can be positioned at MHSBM and other marinas in Gibraltar to raise awareness within the local boating community and allow for easy implementation of cleaning and monitoring measures. In recent years, researchers have increasingly found that the inclusion of local populations can aid in raising awareness and the facilitation of monitoring measures. Marine management of invasive species is now a priority for international and regional governing bodies. Of particular importance to the Department of Environment, Sustainability, Climate Change and Heritage (DESCCH), is descriptor number 2 of the Marine Strategy Framework Directive (MSFD) concerning marine non-indigenous species and the requirement to maintain levels of non-indigenous species introduced by anthropogenic activities at levels which do not alter the ecosystems. As it stands the Good Environmental Status (GES) of this descriptor is not met in BGTW. The incorporation of benthic surveys and the implementation of detection and monitoring measures to understand the complexity of the issue and work towards a healthier marine ecosystem.

Diverse research using both quantitative and qualitative methods was carried out in order to fulfil my research aims, requiring a literature review stage to gain a background understanding of potential invaders in the area as well as methodologies for detection, in addition to precautionary and mitigating measures in place in other at risk areas (local, national and global). To help inform local government policies, an understanding of international monitoring conventions was needed, notably the IMO Convention focusing on recreational vessels as vectors of introduction and spread of non-indigenous species.

The spread of non-indigenous species is an environmental issue which is vastly underestimated and often overlooked. Seemingly harmless leisure activities can enable the translocation of species and the antifouling coatings used can cause further environmental impact to the already vulnerable marine environment. Raising awareness of the potential of the introduction of NIS into BGTW and the unregulated use of harmful antifouling coatings can be an effective way of reducing the impact, in turn facilitating the monitoring and maintenance costs and reducing environmental pressures. The role played by recreational vessels in the introduction and spread of non-native species has been increasingly researched over the past decades, inclusion of local boating communities in the detection and monitoring of such introductions has proven beneficial. Allowing local citizens to take responsibility for the role they play in the modification of the marine environment will make for positive outcomes and a closer connection to nature. In recent years, populations have largely benefitted from the marine environment and the outlet that it provides from uncertain and stressful times, it is vital that the public are aware of the fragility of coastal ecosystems to allow for generations to come to enjoy the same. The awareness of issues impacting the marine environment in the local community can also ease the pressures on local governments, reducing the costs of monitoring and eradication measures.

Stakeholders involved in my project were the marina operators and boat owners, facilitated by member of the marina committee and project advisor, Ken Ruiz, who facilitated access to the study site. The questionnaire provided a valuable insight into local boatowner behaviour including travel patterns, cleaning regimes and awareness of environmental issues linked to hull fouling. Cooperation with local stakeholders is of particular importance to governing bodies such as the DESCCH, helping to inform policy making and include local communities in environmental protection and conservation, taking a proactive approach to the issues affecting local marine ecosystems.

Expert in the field, José Guerra-García helped with the verification of the identification of the invasive shrimp species, Caprella scaura. Identification of species is essential and can help inform areas requiring further research to understand the temporal and spatial scale of invasions and the impacts they are having on native species.

Future implementations of Rapid assessment surveys in MHSBM and other marinas in Gibraltar as well as further afield were taken into consideration throughout the project, taking measures to allow for the facilitation of survey realisation, training of volunteers, collection of data, preservation of samples. In addition to this, the questionnaire distributed to understand boating behaviour is something which should be rolled out for future surveys as it can not only provide important information, but also lead to positive changes in such behaviour. The combination of the research methodologies used here can help in reducing the potential of future introductions through the roll out of surveys in the marinas in BGTW and the creation of community outreach education programmes positively contributing to a wider understanding of the issues faced by the marine environment by those who are enjoying the leisure and economic opportunities it has to offer. Easy in-water cleaning measures, identification of levels of fouling on vessels and removal of plastic and debris from antifouling coatings can provide foundations for a cost-effective approach to marine management. Another outcome of the project is the identification and cataloguing of native and non-native species, deepening the awareness of the species present and the measures needed to protect any vulnerable species and prevent non-native, invasive species from successfully establishing and spreading further in BGTW and along the neighbouring coastline.

Infographic: raising awareness of hull fouling and invasive species detection.