The use of video-techniques for monitoring and quantification of mobile fauna in marine cultivation systems

Abstract

Introduction 1.1 General introduction 1.2 Aim & objectives of the study 2 Literature review camera techniques 2.1 Methodology 2.2 Literature Review 3 Preliminary tests on video techniques 3.1 Methodology 3.1.1 Study sites 3.1.2 Camera systems 3.1.3 Video analysis 3.2 Results 3.2.1 Mobile fauna in the Eastern Scheldt and North Sea 3.2.2 Baited camera and transects 4 Workshop "Use of advanced tools and video techniques for monitoring and quantification in aquatic environments" 5 Conclusions and recommendations 5.1 Methods for studying marine mobile fauna 5.2 Environmental factors affecting the use of cameras 5.3 Recommendations for the optimization of BRUV systems, deployment and experimental design 6 Acknowledgements 7 Quality Assurance References Justification Annex 1 Supplementary Table Perciformes Callionymidae Callionymus Callionymus lyra Pitvis Perciformes Callionymidae Callionymus Callionymus maculatus Gevlekte pitvis* Perciformes Callionymidae Callionymus Callionymus reticulatus Rasterpitvis Perciformes Caproidae Capros Capros aper Evervis Perciformes Carangidae Trachinotus Trachinotus ovatus Gaffelmakreel* Perciformes Carangidae Trachurus Trachurus trachurus Horsmakreel Perciformes Centrolophidae Centrolophus Centrolophus niger Zwarte vis Perciformes Gobiidae Aphia Aphia minuta Glasgrondel Perciformes Gobiidae Crystallogobius Crystallogobius linearis Kristalgrondel*

Biodiversity monitoring in seaweed farms by DNA metabarcoding using settlement plates and water samples

“…While the overall numbers of individuals in the holdfasts were similar, higher species richness and a different species assemblage were found on the holdfasts of cultivated kelps (Walls et al 2016). Previous studies also suggest that similarly to natural seaweed beds, seaweed farms serve as habitat for fish, especially for juveniles (Bergman et al 2001, Zemke-White and Smith 2003, Tonk et al 2019. On the other hand, seaweed farming can also act as a stepping stone for invasive species or as a reservoir for diseases and pests (Loureiro et al 2015, Bernard 2018, Campbell et al 2019.…”

“…In order to overcome these difficulties, traditional visual assessment can be combined with novel techniques. For instance, camera and video techniques are increasingly being used to assess mobile fauna in the marine environment (Pelletier et al 2012, Tonk et al 2019. Besides this, the use of molecular identification techniques has also increased due to the recent advancements in highthroughput sequencing techniques (Heather and Chain 2016).…”

“…However, it also lowers the possibility to detect pelagic species, such as fish. On the same day the water samples were collected in the onshore farm in the Eastern Scheldt, underwater video techniques were applied to investigate the mobile fauna in the farm (Tonk et al 2019). Horse mackerel (Trachurus trachurus) and big-sand smelt (Aterina boyeri) were observed in the farm by video recordings (Tonk et al 2019), but they were not detected by DNA metabarcoding, although marker sequences of both species are available on Genbank (NCBI).…”

“…Furthermore, three jellyfish species were detected by baited cameras (Tonk et al 2019) but not by DNA metabarcoding, although 18S sequences of all three species are available on Genbank (NCBI). Thus, the use of water samples for biodiversity analyses requires further preliminary tests before it can be used for reliable assessments in order to ensure that all species present in the farm can be detected.…”

Baited camera to identify macro-fauna species and their abundance in close proximity to seaweed farms : technical report

“…A recent study in the Eastern Scheldt, an inshore delta system in the south of the Netherlands, has shown a great abundance of the amphipod Caprella spec. on introduced seaweed cultivation ropes, but an overall low diversity of meso-fauna (Bernard & Tonk 2019). Nevertheless, these amphipods may be part of the diet of many carnivore and omnivore fish.…”