Navigating Ecological Considerations and Sustainability in Mariculture Practices (Vlaams Aquacultuursymposium 2024)

Like on land, space at sea is limited and highly contested. Offshore developments reduce fishing grounds for trawlers but open new spaces for alternative fishing practices. Within the SYMAPA project, we explored the initial steps toward coexistence between passive fishing and mariculture at a site off the Belgian coast. This talk will highlight project work focused on fisheries techniques and explore possible synergies between passive fishing and mariculture, with a case study on mussels and cuttlefish.

Bio: Jasper van Vlasselaer is a marine biologist and researcher specializing in fisheries techniques at the Flemish Institute for Agriculture, Fisheries, and Food (ILVO). His work primarily addresses the Belgian fisheries sector, focusing on minimizing environmental impact and enhancing catch selectivity. Recently, Jasper has been researching pot fishing as an alternative fishery method, and he is currently pursuing a PhD examining species attraction to pots.

Inshore aquaculture of marine molluscs (e.g., the suspension-feeding cockle Cerastoderma edule) might be an alternative practice if cost-effective and nature-based technology enhances their growth and survival. Our experiments in a former polder where tides acted as a natural pump for seawater revealed an increase in the quality of the water (i.e. reduction in sediment loads and stimulation of pelagic microalgal growth) and that of the cockles (shell growth and meat content). These results suggest that inshore aquaculture of marine shellfish may provide sustainable food and income for coastal communities, in particular when the shellfish farms are located in low-lying salinized coastal areas where common agriculture practices are no longer profitable.

Bio: Katja Philippart is a senior scientist at the Royal Netherlands Institute for Sea Research, a professor on marine cology at the University of Utrecht and the director of the Waddenacademie. The main aim of her research is to understand the trophic interactions between the main primary producers (phytoplankton and microphytobenthos) and primary consumers (bivalves) of shallow temperate coastal waters such as the Wadden Sea. Hereto various techniques are used, including automated monitoring networks, field surveys, remote sensing (airborne and satellite) techniques and laboratory experiments under controlled environmental conditions. Collection and advanced statistics of field data and testing of mechanistic views on structuring factors of primary production and consumption in shallow coastal waters is performed within multiple interdisciplinary projects, performed together with national and international partners.

In my presentation,  I want to discuss the issues we face as producers of sturgeon or other fish species in RAS systems. Namely, the considerable additional costs compared to open systems and (over)regulation compared to foreign countries. This translates into unequal competition that makes it extremely difficult to engage in intensive aquaculture in Flanders.
We can only sustain ourselves in this highly competitive market by distinguishing ourselves from our competitors with our quality and services.

Bio: Willy Verdonck, obtained his PhD about Breeding sea bass in warm water effluent in Leuven in 1989. After his studies, he started as general nutritionist at N.V. Joosen-Luyckx, with a speciality in fish feed. He co-founded Aqua-Bio within the Joosen-Luyckx group, as producer of Belgian caviar.

Sustainable production of food from the oceans is a priority with increasing awareness. In line with this global interest, aquaculture-related activities in Flanders (Belgium) have been growing over the last two decades. Both industry and government are investing substantially in local aquaculture initiatives. However, they all face one common problem: the lack of starting material (bivalve spat, shrimp larvae and seaweed spores) in sufficient quantities and desirable qualities. Within the BlueMarine³.Com project, we adapted hatchery and nursery concepts for molluscs, crustaceans and macroalgae to local conditions and expanded our biological and technological knowledge on cultivation techniques. Throughout the project, there is a strong emphasis on synergies, in function of sustainable and responsible use of all resources needed for proper larviculture.

Bio: Vincent Vermeylen has a background in biology and currently works as a scientific researcher at the Lab of Aquaculture and Artemia Reference Center at Ghent University, which is a member of the Belgian EMBRC node. His work focuses on aquaculture research, and he is involved in studies related to larviculture, life feed and aquatic health.

Feed plays a critical role in aquaculture, as over 70% of farmed seafood is fed, and feed production can account for up to 90% of environmental impacts in the industry. These impacts, often linked to deforestation, land conversion, and unsustainable fisheries practices, highlight the need to reduce feed-related environmental harm. Due diligence in sourcing feed ingredients is essential to managing these impacts effectively.

Bio: Maurane Martin Hernandez, Market Development Manager for Belgium at the Aquaculture Stewardship Council (ASC) will explore how the ASC Feed Standard contributes to restorative aquaculture through responsible sourcing and risk assessments of feed ingredients.

Increasing development of infrastructure for offshore renewable energy presents an opportunity for the restoration of a nearly extinct native habitat, the once extensive European flat oyster reefs of the North Sea. Here, a collaborative approach between industry, research, and aquaculture is proposed along with a methodology for upscaling restoration supported by proof of concept in early project results.

Bio: Molly Hughes is a PhD student at the Laboratory of Aquaculture and Artemia Reference Center at Gent University. Originally from the United States, Molly’s professional background includes coastal restoration, fisheries management and more recently, offshore aquaculture development in the Belgian part of the North Sea. Her current work as a doctoral candidate is focused on upscaling restoration of the native European flat oyster, Ostrea edulis.

The Artificial Hard Substrate Garden is an in situ experimental platform designed to support research on the interactions between man-made structures and the marine environment, aiming to support sustainable offshore development. In this talk we will showcase practical examples of how the AHSG has supported restorative aquaculture, discuss future outlooks and outline how we can support the aquaculture practitioners of tomorrow. 

Bio: Wannes De Clercq is a marine biologist at the Institute of Natural Sciences, passionate about marine conservation and experienced in the effects of mariculture on benthic communities. Within the Institute, he manages the ‘Artificial Hard Substrate Garden’ (AHSG) and provides it as a research service at both the Belgian and European EMBRC level.

Numerous projects across Europe are working to restore oyster reefs, which were once a crucial ecosystem in northern Europe. However, restoration efforts are hindered by limited larval availability. This study investigates how oyster aquaculture could support reef restoration and offers modelling tools to assist in selecting suitable sites and optimizing the placement of flat oyster restorative aquaculture initiatives.

Bio: Brecht Stechele, Ph.D. is an environmental engineer, with a passion for the marine environment. Alongside his engineering degree, he pursued a second Master’s degree in Marine Biodiversity and Conservation, broadening his understanding of sustainable management practices for marine ecosystems.
His experience in the marine domain includes an internship at the European Commission and relevant legislative experience as a marine policy advisor for the Belgian Federal Government. During his employment at Ghent University, he contributed to innovative research projects developing the aquaculture technologies for blue mussels and flat oyster cultivation in offshore wind parks in the open North Sea. His doctoral research focused on restorative aquaculture of flat oysters, proposing innovative ecological and technological approaches for large-scale offshore oyster reef restoration.
Currently, Brecht provides consulting services, offering creative solutions for nature restoration initiatives. He collaborates with various organizations and research institutes dedicated to scale up marine conservation and restoration efforts all over the world.

Volume calculations based on multibeam water column data show great potential to assess the growth stage of bivalve dropper lines. This technique may provide aquaculture managers a reliable, cost-effective tool to predict the optimal time to harvest the bivalves. In order to allow volume calculations, the multibeam water column data need to filtered and clustered, allowing to obtain volume calculations for each individual dropper line. Open access scripts have been developed enabling these steps and providing an onset towards automatic volume estimates.

Bio: After graduating in 2010, Thomas started as a teaching assistant and PhD-student at Ghent University, Department of Geology, focusing on contourite deposits and cold-water corals along the Moroccan Atlantic margin. After his PhD, Thomas was appointed senior marine technician at Flanders Marine Institute in April 2017, but gradually became a project manager for infrastructure-based research projects, focusing mainly on multibeam water column data. One of the research lines is the application of multibeam data for aquaculture purposes. Currently, Thomas divides his time between maintaining (acoustic) equipment, acquiring and managing research projects and managing large infrastructure projects.