BACKGROUND
Last summer we agreed to the deployment of a multi-element sediment enrichment experiment around the Barkley Canyon Pod 3 camera. This represented the first in situ manipulative experiment on the NEPTUNE network, although we have a history of caged faunal-exclusion and forensic (pig deployments) experiments on the VENUS network in Saanich Inlet and the Strait of Georgia (see comment below). The Barkley Canyon organic enrichment experiment was deployed during the Falkor cruise in September and will be terminated in May with the collection of push cores and removal of the 18 square frames. We subsequently agreed to the one-year deployment of blocks of whale bone and carbonate substratum at the same experimental site, beginning in May this year, on behalf of Craig Smith (Univ. Hawai’i) and Lisa Levin (Scripps Institute of Oceanography). Also, forensic scientists from Simon Fraser University have also expressed an interest in deep-water pig carcass deployments in Barkley Canyon. Finally, for the past two weeks, we have been corresponding with Craig Smith about the feasibility of deploying an entire large whale carcass (from a future stranding) at a deep-water site on the NEPTUNE network, with Barkley Canyon being a primary candidate site. A whale carcass and skeleton would become a permanent feature of the observatory, since the whale bone communities appear to persist for decades.
EXPERIMENTAL SITE PROPOSAL
We need to go beyond ad hoc management of requests for manipulative experiments and consider designating certain sites as “experimental areas”, where we can schedule, deploy and recover experiments, and maximize community participation in experimental observations and the interpretation of results. Regardless of whether ideas for experiments come from individual investigators or groups, the Ocean Networks Canada open data policy and the collective nature of our facility, will ensure that anyone can access all experimental observations. I propose therefore that we designate two areas in Barkley Canyon for experiments involving, in a first instance, the addition of substrata or organic enrichments. One site would be to the east of the Hydrates junction box, reachable by the tracked vehicle Wally, and a second site at the Pod 3 camera. This would leave Pod 1 (canyon axis), Pod 2 (upper slope) and Pod 4 (mid-canyon) reserved for long-term observations. Experimental proposals would be reviewed by ONC and the benthic processes research community, for their technical feasibility and their potential impact on passive observations. We would leave the scientific merit review to the funding agencies.
8 Comments
Dwight Owens
Your comments are invited. Please add your ideas and suggestions by clicking Add Comment below. (Include your initials so we know who makes which comments.)
Anonymous
Something to keep in mind is that monitoring of a whale carcass, especially if remotely operated vehicles are involved, might also create acoustic and/or seismic noise which could interfere with e.g. hydrophones and seismometers.
Marjolaine Matabos
There is only 70 m between POD3 and POD4, considering the size of a whale carcass and how long it lasts on the seafloor, couldn't this impact eventually observations at POD4? We mentionned at the workshop in Halifax in 2012 the possibility of moving platforms. Maybe it would make sense to move POD3 and even re-think the layout of instruments among the two platforms (e.g. sediment trap and plankton pump on POD4)?
I'm not a PI on any of Barkley instruments, this is just a thought. That would require a longer cable between POD3 and POD4...
Anonymous
I am concerned about the potential impact of the manipulations. Having the area around Pod 4 remain unimpacted is critical as long as it is unimpacted. I don't think Craig is putting down a carcass, isn't it just bone?. We can ask the PI who is doign the manipulation to justify the size of the predicted impacted area is within a certain radius (e.e. yes to bones no to whales). We should move instruments around including those for basic monitoring (eg. camera, plankton pump (yeah right), sediment trap, current meter).
Anna
Anonymous
As explained in my Background and Site Proposal texts above, Craig is first proposing to place whale bones at the Pod 3 camera site. The whale carcass, if approved, could be placed at Pod 3 or near Hydrates.
Renald Belley
I think POD3 can be a valuable site for small-scale manipulative experiments (e.g. Neus organic enrichment experiment, the one-year deployment of small blocks of whale bone and carbonate substratum) without disturbing the area around POD4 as mentioned by Anna.
The whale carcass will most likely attract fauna in a large radius (500 m to 1 km?) and affect the location on the long-term. If PIs agree to the long-term disturbance of Barkley Hydrates, it seems like a good place for the whale carcass experiment. The main concern would be area disturbed by the whale carcass. There is about 500 m between the Hydrates and Mid-Canyon, will that be enough to don't attract all mobile fauna (e.g. fish species) from POD4 and POD3 to Hydrates and change the video analysis results at POD3 and POD4? It would be a good idea to have the predicted impacted area if the location is adequate and if some instruments should be moved.
I'm also not a PI, so this is just my two cents!
Fabio Cabrera
Hi all,
here are my comments on the influence of a large whale carcass on the seafloor. There has been several articles published that suggest the effects of a large whale carcass on seafloor community structure do not exceed 10 meters (Smith and Baco, 2003, Treude et al 2009, Smith et al in review at MEPS). Specifically, all of these articles show no detectable effects on macrofauna, meiofaunal or geochemistry (porewater or water column) at distances beyond 9 m. A 20 m radius is very conservative in ensuring that there are no biological or geochemical impacts, except for megafaunal scavengers (Renald's comments). I have attached all these references here to this wiki page.
Anna, replying to your comment. Initially we are planning to deploy only small whale bones (3 rib pieces) in front of POD3's camera, but as Kim has communicated a large whale fall experiment is under discussion not only for scientific purposes but also for a benchmark BBC film documentary, which could potentially draw a lot of public awareness for our observatory and spark many other research collaboration initiatives.
However, Marjolaine's, and Anna's comments are pertinent and we should discuss this in detail during our meeting next Tuesday (11 of March, 2014 at 8:100 am PST). Dwight, is it possible for us to get alerts when new comments are added to this page? Thanks, hope we can chat about this during our conference call next Tuesday.
Mairi M.R. Best
"This represented the first in situ manipulative experiment on the NEPTUNE network, although we have a history of caged faunal-exclusion and forensic (pig deployments) experiments on the VENUS network in Saanich Inlet and the Strait of Georgia."
Actually there have been shell and wood experiments deployed on both VENUS and NEPTUNE in the past. On the VENUS network they were in Saanich Inlet starting with the first deployment in 2006. On the NEPTUNE network, these have been deployed at the Gas Hydrates (see project listing) since May 2010. Details of these experiments are described in this document Role of skeletal assemblages 2011.doc. An example of the deployment can be seen in this image non hydrate experiment Oct 20 455pm EDT.jpg and by searching "shell experiment" in SeaTube. Any questions, please contact Mairi Best (mmrbest@gmail.com).
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