Effects of ocean acidification on lobster behaviour
The experiments will be carried out by Dr. Anna-Sara Krång as part of her research visit at NTNU, in collaboration with Prof. Gunilla Rosenqvist, Department of Biology, NTNU.
The purpose of the research project is to identify effects of climate changed related decrease in seawater pH levels (ocean acidification, OA) on lobsters. The behaviour of the lobsters will be studied in different experiments, after exposure to OA (at levels predicted for year 2100 and 2300) for up to two months (alone or sometimes in combination with microplastic pollution). Behaviours investigated will include boldness (e.g. exploration of novel environments and objects), dominance establishment (by observing interactions of size-matched lobsters on two consecutive days) and time spent between food search and predator avoidance (using only predator odour). In addition, the project aims to identify how OA affects the ability of lobsters to detect odours, by measuring changes in activity of chemosensory neurons with electrophysiological techniques (since the chemical signal becomes an electrical signal in the lobster).
The results from this research are important to understand the biological effects of OA, and ultimately how this affects species’ populations. The results will form a basis when authorities enact legislation and develop assessment criteria for marine environmental health. Additionally, the experiments will lead to a better fundamental understanding of the early benthic phase of lobsters, of lobster olfaction, chemosensory disruption in marine animals, as well as of interactions between OA and pollutants. Since lobsters are commercially important, this research is important to the fishing sector and for stock management. Increased knowledge of personalized behaviour related to boldness and aggression may also contribute to overcome some of the problems associated with lobster cultivation, which in turn will reduce the fishing pressure on wild lobster populations.
The experiments will be conducted on decapod crustaceans. Primarily different stages of the early benthic juveniles of the European lobster (Homarus gammarus) will be used in the behavioural experiments. The juvenile stage is of particular interest since it is considered a bottle-neck phase in their life cycle, and very little is known about their habits and behaviour. Some behavioural experiments will also be conducted on adult European lobsters, and possibly on adult Norway lobsters (Nephrops norvegicus). For the behavioural experiments ca. 20 lobsters will be used per treatment, giving a total of 60-120 lobsters per experiment. Up to three behavioural experiments will be performed. Some behavioural experiments will be followed by respiration measures, performed on the same individuals (both only cause minimal distress). A maximum of 20 antennae from adult lobsters of each species will be used for the electrophysiological experiments. All experiments will follow Norwegian and European agreements and legislation. The facilities have necessary authorizations and responsible personnel involved have long-term training in experimental work with decapod crustaceans. All work will be outlined to minimize stress, to reduce handling and sampling procedures and the total number of animals, but at the same time not jeopardizing the statistical power and scientific values.
The purpose of the research project is to identify effects of climate changed related decrease in seawater pH levels (ocean acidification, OA) on lobsters. The behaviour of the lobsters will be studied in different experiments, after exposure to OA (at levels predicted for year 2100 and 2300) for up to two months (alone or sometimes in combination with microplastic pollution). Behaviours investigated will include boldness (e.g. exploration of novel environments and objects), dominance establishment (by observing interactions of size-matched lobsters on two consecutive days) and time spent between food search and predator avoidance (using only predator odour). In addition, the project aims to identify how OA affects the ability of lobsters to detect odours, by measuring changes in activity of chemosensory neurons with electrophysiological techniques (since the chemical signal becomes an electrical signal in the lobster).
The results from this research are important to understand the biological effects of OA, and ultimately how this affects species’ populations. The results will form a basis when authorities enact legislation and develop assessment criteria for marine environmental health. Additionally, the experiments will lead to a better fundamental understanding of the early benthic phase of lobsters, of lobster olfaction, chemosensory disruption in marine animals, as well as of interactions between OA and pollutants. Since lobsters are commercially important, this research is important to the fishing sector and for stock management. Increased knowledge of personalized behaviour related to boldness and aggression may also contribute to overcome some of the problems associated with lobster cultivation, which in turn will reduce the fishing pressure on wild lobster populations.
The experiments will be conducted on decapod crustaceans. Primarily different stages of the early benthic juveniles of the European lobster (Homarus gammarus) will be used in the behavioural experiments. The juvenile stage is of particular interest since it is considered a bottle-neck phase in their life cycle, and very little is known about their habits and behaviour. Some behavioural experiments will also be conducted on adult European lobsters, and possibly on adult Norway lobsters (Nephrops norvegicus). For the behavioural experiments ca. 20 lobsters will be used per treatment, giving a total of 60-120 lobsters per experiment. Up to three behavioural experiments will be performed. Some behavioural experiments will be followed by respiration measures, performed on the same individuals (both only cause minimal distress). A maximum of 20 antennae from adult lobsters of each species will be used for the electrophysiological experiments. All experiments will follow Norwegian and European agreements and legislation. The facilities have necessary authorizations and responsible personnel involved have long-term training in experimental work with decapod crustaceans. All work will be outlined to minimize stress, to reduce handling and sampling procedures and the total number of animals, but at the same time not jeopardizing the statistical power and scientific values.