Documenting the recovery of the Sussex inshore ecosystem


Since 1987, over 96% of Sussex’s kelp had been destroyed due to years of harmful human activities with devastating impacts to the marine community. In 2021, a new law prohibited trawling to reverse this decline. This project assesses ecosystem recovery tools to evidence effectiveness of further trawling bans in supporting marine restoration.

Project description

Kelp forests once stretched 40 kilometres along the Sussex coastline, creating one of the most productive and biodiverse environments on the planet. But by the mid-1980s, more than 96% of kelp  had disappeared as a result of years of destructive fishing and various other human-related activities, causing significant harm to the marine ecosystem. In 2021, the Sussex Inshore Fisheries and Conservation Authority (IFCA) introduced a new law, the Nearshore Trawling Ban Byelaw. This pioneering legislation created one of the largest trawling prohibited areas in the UK of 300-square-kilometer area along the Sussex coast in an effort to reverse this ecological decline. 

Effective conservation policy is key to addressing marine ecosystem degradation. This research project assesses ecosystem recovery using environmental DNA (eDNA), a revolutionary ‘disruptor’ technology for biological assessment of aquatic systems, to evidence effectiveness of further trawling bans in supporting the recovery and regeneration of the marine environment. Our Aquatic Research and Knowledge exchange (ARK) group at the University of Sussex has been leading on the Sussex Kelp Restoration project monitoring recovery. In this project SSRP researchers toether with local partners apply emerging environmental DNA (eDNA) biodiversity monitoring technology to assess the effectiveness of the pioneering 300km2 Sussex Trawler Exclusion Zone (TEZ) established in 2021, and local Marine Conservation Zones (MCZ), in biodiversity recovery and protection.

Through this research project, the team aims to:

  1. undertake eDNA marine survey 2024,
  2. compare annual biodiversity metrics (species diversity metrics, multivariate community structure/function metrics) since initiation of TEZ (2021) to assess ecosystem recovery,
  3. compare cost-effectiveness of eDNA against standard Baited Remote Underwater Video (BRUV) survey.

Addressing three SSRP themes of Planetary health, South Coast sustainability and Sustainable climate and food systems, the team will document the recovery of the Sussex inshore ecosystem post Trawling Byelaw using environmental DNA (eDNA), in conjunction with other monitoring techniques. The project particularly focusses on SDG 14 Life Below Water, specifically 14.2.2 Sustainable Fisheries, 14.3.4 Technologies towards aquatic ecosystem damage prevention, and 14.5.2 Monitoring the health of aquatic ecosystems. Building on the team's ability to document the success of marine protected areas and other restoration strategies is paramount to the goal of protecting 30% of the global ocean by 2030, as proposed by the EU Biodiversity Strategy and the Convention on Biological Diversity. 

Timeline and funding


November 2023 - July 2024


SSRP funding (£19,560)


To gain valuable insights into the effectiveness of marine ecosystem recovery strategies, this project encompasses the following three key methodological steps:

1. Sample Collection:

  • collect eDNA from 28 sites within the TEZ, MCZ and unprotected areas, with samples then being processed for metabarcoding (Naturemetrics) to identify species present (fish/vertebrate primers)

2. Data Analysis:

  • determine diversity indices from summary species tables (R Vegan package)
  • conduct multivariate analysis of community structure and function (Canonical Correspondence Analysis in R Vegan) to assess temporal changes since 2021 in the TEZ and evaluate the effectiveness of MCZs in promoting ecological recovery

3. Indicator Taxa Analysis:

  • identify species indicative of ecosystem recovery through indicator taxa analysis (R indicspecies).

Expected outcomes and impacts

The research team aims to achieve three significant outcomes:

  1. assess status of ecosystem change since initiation of TEZ and effectiveness of MCZs
  2. determine cost-effectiveness of eDNA technology compared to standardised Under water visual survey (BRUV)
  3. guide national and international scaling of trawler bans to promote ecosystem recovery.

It is expected that marine governance strategies, such as TEZ and MCZ, underpinned by scientific evidence of being effective, will support the broader application of trawler exclusion measures in ecosystem recovery efforts at national and international levels.

On a larger scale, the restoration of the Sussex coastal ecosystem is playing a major role in building local awareness of the biodiversity and climate crisis. A recent BBC documentary highlighted the role of local citizens in calling for environmental protection. The project engages undergraduate, Masters and PhD students as well as local stakeholders in undertaking annual surveys, building local awareness in marine conservation. The project aligns with the Environment Agency’s mission to restore 15% of priority habitats along the English coast by 2043 and supports DEFRA's 25-year Environment Plan focusing on coastal kelp restoration.

Furthermore, a 2022 ecosystem services valuation shows that restoring kelp to its historical distribution could deliver a range of economic benefits and services estimated at £3.5 million. These include provisioning for commercial offshore fisheries and small-scale inshore fisheries that benefit from the spillover effect of the marine protected area, coastal protection as the kelp absorb storm impacts, carbon sequestration, nursery habitats for fish and other commerically valuable species and cultural services like diving and tourism.

Educationally, this research contributes to the understanding and development of policy issues and/or capacity building in relation to specific developmental challenges. The study of ecosystem recovery following trawler exclusion, and the use of a unique combination of monitoring technologies, has global implications for fisheries and marine restoration management, applicable to both regulatory and commercial contexts. This current project plays a major role in engaging students in ‘action research’ with previous work by the project team having already generated: two Junior Research Associate posters, ten 3rd-year dissertations, six Master theses, and two PhD theses, and one journal article in press (Clark et al., 2023). Direct project outputs will include one peer-reviewed journal article and one Master thesis.

Overall, this research directly supports UK ecosystem recovery, climate change mitigation and improves local and region ecosystem services. 

Related work

Our Aquatic Research and Knowledge exchange (ARK) group at the University of Sussex has been leading on the Sussex Kelp Restoration project monitoring recovery.

This project builds on previous research which has already generated substantial media coverage. Media and short films summarising work by staff and students include: i) Reviving the UKs underwater kelp forests and ii) Sussex Kelp Restoration Project Science Film.  

The team

Where we worked

Sussex, UK.