Settlement and Behaviour of Marine Fouling Organisms

Abstract

This chapter defines the term settlement, as it applies to marine biofouling, and outlines the stages and levels of complexity involved in the process. It is beyond the scope of this work to present an exhaustive review of the literature, instead the work aims to outline some broad patterns and provide examples from the wealth of research that exists. The processes of surface encounter and attachment are given particular attention, as well as the role of environmental cues and passive and behavioural responses to them, whilst highlighting the pitfalls associated with inferences made without direct observation. Finally, there is a substantial resource table, summarising the species studied, the cue or influence on settlement, and a brief summary of the findings. IntroductionMany fouling species naturally occur in distinct zones (Plate I C), and three possible hypotheses were originally proposed to explain this phenomenon, namely (i) larvae settle randomly and those that do not encounter a suitable site die, (ii) species with a motile adult stage settle randomly then migrate to or are confined to an area based on species-specific biotic or abiotic factors and (iii) larvae may congregate at a particular depth in the water column when they are ready to settle. Since then it has been realised that larvae of many species are capable of sophisticated site-selection behaviours during settlement, as adaptations that maximise the likelihood that a site with an appropriate combination of biotic and abiotic factors (niche) will be arrived at.Species settlement is not the same phenomenon as recruitment. For the purposes of this chapter, settlement is defined as the process that follows the planktonic phase and precedes metamorphosis, and at the most basic level it involves surface encounter and attachment. Once settlement and metamorphosis has occurred, marine macrofouling organisms are immobile species that grow attached to artificial structures. The most notable of these belong to both algal and invertebrate groups: Algae, Mollusca (e.g. mussels), Crustacea (e.g. barnacles), Bryozoa, Annelida (e.g. tubeworms), Tunicata (colonial and solitary forms), Cnidaria (corals, anemones and hydroids) and Porifera (sponges). As settlement marks the transition from the planktonic to the sessile phase, it has logically become a focus of intense research. From a biofouling perspective, it is of major importance to understand the processes that influence settlement, as 30 Biofouling Edited by Simone Dürr and Jeremy C. Thomason

Effects of substratum type on bacterial community structure in biofilms in relation to settlement of plantigrades of the mussel Mytilus coruscus

“…Substratum type has been known to affect larval settlement and metamorphosis of many marine invertebrates (Prendergast, 2010). For example, young cyprids of the barnacle Balanus amphitrite settled on more on glass than on polystyrene (Rittschof et al, 1984).…”

Plantigrade settlement of the musselMytilus coruscusin response to natural biofilms on different surfaces

“…Surface wettability may regulate patterns of cell accumulation and cell distribution during the early stages of biofilm development (Terlizzi & Faimali, 2010). In addition, surface wettability is one of the major factors influencing larval settlement of many marine invertebrates (Prendergast, 2010), e.g. the bryozoan, Bugula neritina (Rittschof & Costlow, 1989;Gerhart et al, 1992), the mussel, M. galloprovincialis (Carl et al, 2012), the barnacles Balanus amphitrite (Rittschof & Costlow, 1989) and B. improvisus (Dahlström et al, 2004) and the ascidian, Ascidia nigra (Gerhart et al, 1992).…”

Mechanisms and impact of differential fouling of the zebra mussel Dreissena polymorpha on different unionid bivalves

“…Macrobiofouling of hard substrata by sessile organisms, such as algae, bivalves, polychaetes, barnacles, ascidians, sponges and cnidarians is an important phenomenon in the aquatic environment (Khalaman, 2001;Prendergast, 2010), causing severe economic losses due to the overgrowth of hydrotechnical appliances and contributing to habitat formation by gregarious ecosystem engineers (Sousa, Guti errez, & Aldridge, 2009;Terlizzi & Faimali, 2010). Hard-shelled animals, including mobile taxa, also suffer from macrofouling ( Duri s, Hork a, & Petrusek, 2007;Strayer & Malcom, 2007;Yohannes, Ragg, Armbruster, & Rothhaupt, 2017) and have developed numerous chemical and mechanical defences against this process (Bers, Prendergast, Z€ urn, Head, & Thomason, 2006;Bers et al, 2010;Hirota, Okino, Yoshimura, & Fusetani, 1998).…”