During the planned research cruise with RV SONNE II, the South Chilean fjord and canal system shall be investigated in response to two devastating harmful algal blooms (HABs), which in the first months of 2016 destroyed almost the entire Chilean salmon production and causing a closure of several months of shellfish harvesting sites and aquacultures, in order to gain insights into the plankton dynamics and, in particular, the dynamics of HAB species. HABs have been known in Chile for years, but their extent and geographical distribution have increased considerably in recent years. In the context of global climate change, an expansion of habitats towards higher latitudes is generally expected, but the opposite is true in Chile, as HABs are spreading northwards. To this extent, Chile is a special system which is not understood. Two hypotheses will be tested within the framework of the expedition:
- HAB species are experiencing a northern distribution extension due to the presence of existing cyst beds (resting stages) with changing environmental conditions allowing for the establishment of new populations;
- HAB species are experiencing a northern distribution extension due to the introduction of new species either by northward migration with the Humboldt Current from the south or from other locations through anthropogenic activities.
In order to examine these hypotheses, a multidisciplinary research program for the determination of parameters of biological and physical oceanography, hydrography, biooptics, marine chemistry, planktology and microbiology is proposed.