HAREST

The HAREST (HAbitat REhabilitation STrategy) is designed to rehabilitate habitats impacted by coastal construction work for fish and invertebrate populations, by offering artificial habitat structures adapted to local environmental and ecological conditions. HAREST includes a combined visual and acoustic monitoring system to track the strategy efficiency through biodiversity indicators of colonization and repopulation.

The Habitat Rehabilitation Strategy (HAREST) will be designed to provide a tailored combination of habitats in order to:

Rehabilitating degraded habitats and mitigating habitat loss related to construction work
Enhancing local marine biodiversity
Improving populations of marine organisms by providing suitable habitats for all life stages, especially vulnerable ones, thus increasing their chances of survival (e.g. larvae, juveniles, crustaceans mature individuals in moulting stages…)

Most recent research in artificial habitat design highlights the fact that the design should take into account site specificities (Figure 3). The HAREST solution developed under the AGESCIC project presents two main added values to other artificial habitats:

HAREST is a strategy that will be developed to accommodate most of the different marine environment scenarios of coastal construction. Practical recommendations to help with the design and implementation of a habitat rehabilitation strategy on coastal construction sites will be specified.
As part of the HAREST, an integrated autonomous monitoring system including visual and acoustic data acquisition, will be developed. This system will allow rapid and regular assessment of the habitat performance in terms of biotic colonization.

The design of the strategy for the rehabilitation of habitats degraded by the proximity of the costal construction work will take into account local environmental conditions of the deployment site. The main objective of the strategy is to locally restore the main ecological functions degraded by the increase of environmental turbidity and noise. The selection of the ecological functions to be restored will depend on the targeted species / habitat considered at the deployment site as artificial reef (AR) design and performance need to suit the biological / environmental requirements. Both local environmental conditions and ecological rehabilitation objectives will determine AR units design, material, number of replicates and exact deployment location.

As the evaluation of the HAREST performance is essential, The UPC will design the various protocols based on underwater visual monitoring as well as acoustic census. Visual and acoustic monitoring protocols will be adjusted to the specificity of the AR design.

In combination with the monitoring protocol, under HAREST the UPC will look at developing a monitoring solution that uses passive acoustics to assess the health at the ARs and to track the increase of biological activity over time; the health assessment and tracking are based on direct acoustic cues from fish, crustaceans, etc., and the computation of ecoacoustic indicators. In addition, the system can include visual observation with an underwater camera which is useful at locations with low turbulence/turbidity. Such a combined monitoring system has already been in development by the UPC for in-air monitoring in e.g. the Mamirauá Reserve (Amazonia, Brazil) and can be redesigned in a water-proof housing for deployment in the water column or on the sea floor in areas containing ARs.

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