Responses of early-life stages of coastal marine invertebrates to different environmental variables

• Main Author: Espinosa-Novo, Noé
• Other Authors: Boersma, Maarten, Zimmer, Martin
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2023
• Subjects: Multiple drivers; native and non-native crab species; larval stages; North Sea and North Atlantic Ocean; Hemigrapsus sanguineus; Carcinus maenas; Hemigrapsus takanoi; 570; 570 Life sciences; biology; ddc:570; North Atlantic
• Online Access: https://media.suub.uni-bremen.de/handle/elib/7483; https://doi.org/10.26092/elib/2706; https://nbn-resolving.org/urn:nbn:de:gbv:46-elib74838

Quantifying species responses to the effects of changing environmental conditions is critical for a better understanding of how climate change affects invasion, expansion, and contraction of marine coastal species. Climate change is leading to modifications in the marine coastal environment, to conditions not experienced before; climate change results in that marine organisms experience simultaneous changes in several environmental variables (=drivers: e.g. temperature, salinity, food). How simultaneous changes in multiple drivers are experienced depend on species-specific traits (e.g. physiological tolerance, developmental time); for instance, co-occurring native and non-native species may experience and respond to climate change in different ways. In addition, within species, responses to multiple drivers may vary across populations and environmental gradients. The general objective of this thesis was to quantify the effects of environmental drivers (temperature, salinity and food limitation) on performance of native and non-native species with focus on larval stages and using crabs as model systems. There were two main objectives, first to compare native and non-native species in the responses to multiple environmental drivers and to quantify larval responses to temperature across their distribution range. I focused on larvae because they play a critical role in population dynamics: larvae are important for the dispersion and connectivity of populations, and are more sensitive to changes in environmental conditions than adults. I used three ecologically relevant species of coastal areas of the North Sea and North Atlantic Ocean as models: Hemigrapsus sanguineus, Carcinus maenas and Hemigrapsus takanoi. C. maenas is native to Europe; Hemigrapsus spp. are both non-native species in the European coast, where they coexist with C. maenas as juveniles and adults in the benthos. I used factorial experiments rearing larvae from hatching to megalopae at different combinations of temperature and other environmental ...