| dc.description.abstract | The six areas of research of COPAS Sur-Austral are devoted to understanding and providing oceanographic information and knowledge for sustainable development of marine Chilean Patagonia. Our work for the past 8 years has distilled in three main themes:
1. Oceanographic basis to understand the aquaculture component of fjord ecosystems
2. Patagonian glaciers and rivers as drivers of fjord circulation, biological patterns, and microbial metabolism
3. Ecosystem approach to understanding Patagonian food webs and fisheries under changing environmental conditions
Within each of those overarching themes, and at different pace, research is generating applications along the way (shown as boxes in section III), which we envision as “research with considerations of use” (Stokes 1997. Quadrant Model of Scientific Research) of COPAS Sur-Austral, in the spirit of the Base Financing Program of CONICYT.
Our long-term observation has allowed to unraveling relations between natural cycles of productivity in Patagonian fjords with main physical forcing in the region. This physical modulation of fjord productivity has implications for carbon fluxes and oxygen budgets, as well as for capacity of fjords to sustain aquaculture activities. This level of understanding specific to Patagonian fjords is necessary to identify main state-variables, key processes, and sensitivity of fjord ecosystems to perturbations such as input of organic and inorganic by-products from salmon farming. We are incorporating study of xenobiotics (pharmaceuticals) and pathways of their incorporation in carbon cycle of coastal ocean.
Over the past year we have learned more about the way in which freshwater inputs and their interaction with oceanic wind forcing determine changes in hydrography and circulation of Patagonian fjords. A recent analysis of spatial-temporal variability in sea surface salinity images indicates the scale over which Patagonian freshwater may impact the salinity and nutrient composition of surface waters in the southern SE Pacific. An intriguing aspect is the apparent along-fjord and depth pattern of nitrate and oxygen concentrations in summer which are strongly correlated below the pycnocline. Nitrate to oxygen ratio departs from theoretical ratio of 0.12 based on Redfield stoichiometry there that increases towards the surface allowing us to suggest that this departure reaches a minimum during wintertime intrusions, and increases with time at intermediate depths mostly due to the remineralization of organic matter discharged into the fjord’s head by the Baker and Pascua river.
Our work has allowed us to present an integrated working model for dominant taxa and organic molecules according to melting scenarios, and to hypothesize that specialization within the bacterioplankton community for specific DOM compounds occurs at small time frames that influences carbon turnover for the resident bacterial taxa in oligotrophic fjords. On the contrary, in more productive fjords (e. g. Puyuhuapi channel) community structure appears to be related to hydrographic features more than composition and availability of organic matter.
Effects of environm Effects of environmental variability on fisheries resources in Patagonia, on aspects associated with productivity, spatial distribution, connectivity and phenology are being investigated. Interannual variations in timing of ice melting and changes in seasonal peaks of productivity in inshore areas are examples of aspects expected to severely affect environmental conditions faced by fishery resources that yearly utilize fjords and channels for spawning and development. We have learned that GLOF events and topographic features affect distribution of zooplankton and fishes and are expected to affect processes such as transport of planktonic organisms along channels or input of organic matter from the river basins to fjords and ocean.
Superimposed on those regional features, exploited demersal fish populations may respond to remote/large scale or local environmental variability, which has not been clearly determined in Patagonia, although our results point to these larger controls/influences. We revealed that synchrony exists between recruitment variability patterns of demersal fishes across the Pacific (east – west) basin, along the Humboldt Current System, and a common recruitment pattern of Patagonian grenadier in Chile, of hoki in New Zealand and of morwong in Australia correlate with Interdecadal Pacific Oscillation (IPO) and Southern Oscillation (SOI) climate indices of the Pacific Ocean. Incorporation of this information for fisheries management is another challenge.
COPAS Sur-Austral connection with the non-scientific community is in the raise. Two new agreements and collaboration partnership were signed during 2015 (IFOP and Municipality of Penco) that were initiated due to confidence, and there are concrete/serious conversations about a new interesting collaborative association with a fishing company interested in climate change (Pesquera Blumar). COPAS Sur-Austral researchers participated in 25 public bodies as part of Working Groups, Expert Groups, Scientific and Technical Committees, allowed to collaborate and contribute with their expertise in the decision making processes such as fisheries and marine red tide toxins, seaweeds, climate change, territorial planning, allocation of time use research vessel, CIMAR fjords Program, among others. During 2015 we were involved in two transference initiatives on cultivation technology of seaweed luga to artisanal fishers in Aysén.
There are two relevant backbones in our research that we are relevant for positioning ocean information in the decision-making equation: a) generation of real time oceanographic continuous observations that are basis for significant progress shown in this report, and b) incorporation of a more multidisciplinary scientific approach for management and recovery of fisheries, and managements of AMERBS and protected areas. | |
