THE UNIVERSITY OF HULL Effects of hypersalinity on the behaviour, physiology and survival of commercially important North Sea crustaceans being a Thesis submitted for the Degree of Doctor of Philosophy in the University of Hull by Katie Louise Smyth, B.Sc. (hons), M.Sc. (dist) September 2011 i Contents Contents ................................................................................................................................ i List of figures ......................................................................................................................... v List of tables .......................................................................................................................... vii Glossary ................................................................................................................................ ix List of abbreviations used in this thesis ................................................................................ ix Acknowledgements................................................................................................................ x Abstract ................................................................................................................................. xi Chapter 1 General Introduction ...................................................................................... 1 1.1 Salinity ................................................................................................................................ 1 1.1.1 Importance of salinity to aquatic organisms. .............................................................. 1 1.1.2 How crustaceans cope with salinity ............................................................................ 2 1.1.3 Impacts of salinity change on crustacea. ................................................................... 5 1.1.4 Toxicological implications of salinity change .............................................................. 8 1.1.5 Salinity change as an environmental problem .......................................................... 11 1.2 Gas cavern construction in the Holderness area of Yorkshire ......................................... 12 1.3 The Holderness crustacean fishery area .......................................................................... 16 1.3.1 Crustacean fishing .................................................................................................... 16 1.3.2 The East Yorkshire Shellfishery ............................................................................... 16 1.4 Site description ................................................................................................................. 20 1.5 Biology of species studied ................................................................................................ 21 1.5.1 Species to be studied ............................................................................................... 21 1.5.2 Habitat and distribution – Homarus gammarus ........................................................ 21 1.5.3 Behaviour and physiology – Homarus gammarus.................................................... 22 1.5.4 Habitat and distribution – Cancer pagurus. .............................................................. 25 1.5.5 Behaviour and physiology – Cancer pagurus ........................................................... 25 1.5.6 Habitat and distribution – Necora puber ................................................................... 27 1.5.7 Behaviour and physiology – Necora puber .............................................................. 28 1.5.8 Salinity tolerances in the test species ...................................................................... 30 1.6 Crustacean stress, health and metabolism ...................................................................... 32 1.6.1 Cardioventilatory activity ........................................................................................... 32 1.6.2 Autotomy ................................................................................................................... 33 1.6.3 Haemolymph O2 affinity and anaerobic metabolism in crustaceans ........................ 34 1.6.4 Nitrogen metabolism in crustaceans ........................................................................ 35 1.7 Aims, objectives, hypotheses and structure of the thesis ................................................. 37 1.7.1 Aims and objectives .................................................................................................. 37 1.7.2 Structure of the thesis ............................................................................................... 38 i Chapter 2 General Methodology ............................................................................................... 40 2.1 Supply and husbandry of experimental animals. .............................................................. 40 2.2 Experimentation procedure............................................................................................... 43 2.3 Making hypersaline brine .................................................................................................. 43 2.4 Monitoring salinity and water quality ................................................................................. 43 2.5 Statistical analyses ........................................................................................................... 44 Chapter 3 Behavioural assays: Behavioural responses of crustaceans to hypersaline exposure .......................................................................................................................................... 46 3.1 Introduction ....................................................................................................................... 46 3.2 Aims, objectives and hypotheses ..................................................................................... 49 3.3 Materials and Methods ..................................................................................................... 50 3.3.1 Animal husbandry ..................................................................................................... 50 3.3.2 Salinity induced behavioural preference test – Two salinity choice trial .................. 50 3.3.3 Salinity induced behavioural preference test – Multiple salinity choice trial ............. 53 3.3.4 Salinity dependent gender testing for Homarus gammarus ..................................... 54 3.3.5 Salinity dependent gender testing for Cancer pagurus ............................................ 56 3.3.6 Statistical analyses ................................................................................................... 57 3.4 Results .............................................................................................................................. 59 3.4.1 Two choice testing; Necora puber ........................................................................... 59 3.4.2 Two choice testing; Cancer pagurus ....................................................................... 59 3.4.3 Two choice testing; Homarus gammarus ................................................................ 60 3.4.4 Two choice testing; Carcinus maenas ..................................................................... 61 3.4.5 Two choice testing; Pagurus bernhardus ................................................................ 61 3.4.6 Multi choice testing; Homarus gammarus ............................................................... 62 3.4.7 Multi choice testing; Cancer pagurus ...................................................................... 64 3.5 Discussion......................................................................................................................... 67 3.6 Conclusions ...................................................................................................................... 73 Chapter 4 The effects of hypersalinity on mortality of some commercially important crustaceans of the North Sea ....................................................................................................... 75 4.1 Introduction ....................................................................................................................... 75 4.2 Aims and objectives .......................................................................................................... 77 4.3 Materials and Methods ..................................................................................................... 78 4.4 Results .............................................................................................................................. 79 4.4.1 Hypersalinity based mortality calculations for Homarus gammarus ......................... 79 4.4.2 Hypersalinity-based mortality calculations for Cancer pagurus .............................. 81 4.4.3 Hypersalinity based mortality calculations for Necora puber ................................... 82 ii 4.5 Discussion......................................................................................................................... 83 4.6 Conclusions ...................................................................................................................... 86 Chapter 5 Acute and chronic effects of hypersaline exposure and consequences for haemolymph condition in the lobster Homarus gammarus (L.) and the crabs Cancer pagurus (L.) and Necora puber (L.) ..............................................................................................