June 1, 2010
On Safety, Dogma, and Objectivity
Originally published in June 2010 issue of AAUS' E-Slate. Reprinted with permission of AAUS and the author, Jim Washburn, Diving Officer, Oregon State University
Having attended many symposia/conferences over the course of 35+ years (in fact pre-dating AAUS), there have been certain recurring themes that become apparent, as well as a tad perplexing. One theme in particular seems to commonly re-occur during discussions on safety, when using diving as a tool for research. To wit: The never-ending rationale for adding additional dive equipment, by applying the greatest sales pitch of all: SAFETY.
The supposition that one is safer with a pony bottle, and/or two knives, redundant timers, a second regulator, a light (or two), wet and dry suit pockets and attachments, etc., while also disregarding their cumulative effects, needs to be directly challenged by someone, and that someone should be AAUS. We should be in the business of not merely safety, but also facilitating research. We have allowed ourselves to be driven, to a large extent, by the marketing aspects of the diving industry, and thus, have become more than a tad dogmatic.
For the moment at least, let's play in the scientific ball park. Forty years ago, a conventional diver (even in academia) had about 160 total parts of dive equipment. These parts were literally the individual itemized components, e.g., mask (with a strap and buckles), snorkel (including a keeper), fins (including straps and buckles), regulator (with 74 parts), etc. I am sure you get the idea. By the 80s (my last count), the somewhat typical diver was then packing around 74% more parts than a 60s diver. Since the 80s it is reasonable to assume the collection of items, parts, and components has gone far beyond the 282 parts on an 80s diver. The result is an important and largely unaddressed issue for the diver: drag. It is worthy of comment that adding mass to a diver is not a freebee. Mass is, well… mass. Thus, it's subject to all the laws of physics, including inertia. Which leads us to a discussion of drag coefficients (or better yet, power and energy output).
Let us say you have a clone with your identical water skills. Assume you have a moderate additional amount of dive gear, relative to your clone, resulting in 10% less speed (an accurate experimental value), while moving through the water. You say to yourself: "Self: Do I care about the drag, which lessens my speed by 10%?" Answer: You will certainly care if and when speed, and more importantly the ensuing output of energy, is critical. But wait a minute. It is not the additional force which you need to apply to regain your loss in speed that matters. It's really the additional energy (work/time) you must apply to re-gain your 10% loss in speed. And that additional energy is indeed costly. The force required, for example, to push your fins, would be proportional to V2; BUT THE ENERGY YOU EXPEND IS PROPORTIONAL TO V3. This means to regain 10% in speed, you need to apply 33% more energy, i.e., (1.10)3. You may not care if you happen to be elevator diving in Cozumel. But when diving in waves, currents, offshore, and bad visibility, the resulting additional energy requirement can become a far more compelling issue. By the way, I am reasonably certain that the drag on today's diver can become considerably greater than the above example, when adding dry suits, integrated weights, etc. Experimental data is greatly needed. There is no doubt that when your energy output is critical, much of the so-called equipment that you are wearing to allegedly increase safety, is in fact, detrimental to your safety. (emphasis mine-DK) I do not have a problem with any diver making his/her choice to inundate themselves with equipment. However, the issue of equipment choice(s) and their use, which in truth are quite subjective, has become dogma. This does not speak well of the academic diving community. We have an opportunity to influence the dive equipment marketing and manufacturing industry, (not to mention AAUS rank and file), by doing what science and objectivity does best, and that is, have a strong, direct commitment to the fundamental issues, as opposed to the more mundane issues encountered by divers.
Posted by Dida at 2:30 PM
April 5, 2009
The Role of Underwater Photography In Ocean Research
By Stuart Halewood
We’ve all heard the saying “a picture is worth a thousand words.” But to a modern ocean scientist or researcher an accurate image can be worth a whole lot more than that.
In these days of rapidly expanding photographic methods and hardware allowing the melding together of previously unrelated fields of science and the art of photography, the value of a good image is going through the roof.
Why exactly is this so? Well, let’s consider a few examples of the role that underwater photography takes in relation to ocean research.
Take an obvious one, species ddentification. There is hardly a better or faster tool than today’s underwater camera set up to capture a marine subject. We all appreciate a good ID book, but for the researcher the image represents a mass of valuable data. Learning how to take not only a good picture but one that also exhibits the organism’s unique taxonomic identifiable features is of course due to the photographer’s skill and a fair amount of perseverance mixed with luck!
For a species identification shot, it’s important to include identifiable features rather than just be aesthetically pleasing.
Undeniably the educational merit of the sub-surface image is far reaching and diverse: from a teaching tool for trainee Reef survey divers allowing them to collect reliable data, to a photographer publishing a rare species or behavior on the internet and that image then having the chance of appearing in any home across the world. Let us also not forget that as underwater photographers we can make the lay person more aware of what lies beneath the ocean surface in the most unique ways, as well as informing the next generation how life in the ocean affects us all.
We can be the eyes of the person who may never be lucky enough to slip beneath the surface of the ocean themselves.
But wait, back to science and technology! The use of a new generation of cameras allows us to view and record things that would have been impossible –10 years ago. For example:
* The flying eyeball camera is deployed to the sea-bed and takes a picture when it contacts it, allowing extrapolation of seabed sediment particulate size and type
* Hi-speed cameras measure the speed of a mantis shrimp spearing a fish.
* The time-lapse camera sits patiently on the seabed and records bat stars moving not aimlessly but toward each other and touching arms in some sort of communication.
* The in-situ reef camera captures a glimpse of the unknown fish species.
* The deep ocean stereo camera comes face-to-face with the giant squid.
* The camera and strobe fitted with fluorescent filters allows juvenile corals to be seen and counted.
The list goes on and a separate article could be written on each one.
Working in concert with the camera and photographer is the analysis and editing software. This variety of software can expand the image’s usage to a huge degree. Software can now digitize an image and count individual organisms to give spatial densities and abundance, and can go so fine scale as to be able to interpret individual sand grain size and chemical composition of a sea floor without the need of a physical grab sample. This type of non-destructive sampling is especially important to other researchers in fields such as underwater archaeology in identifying artifacts and creating photo mosaics of an entire site. This processing software will evolve in the future and it is hard to say what information may be harvested down the road. The one thing that is certain is that we will continually have to keep upgrading our computers to keep up with our cameras.
If that is not enough there are many more examples of important uses of underwater photography out there; however I’d like to end with one of the most obvious but most essential. That is, highlighting the plight of our world’s marine organisms and habitats. I think that the use of evocative and often shocking images to demonstrate the ongoing damage done to an ecosystem or species by our neglect and lack of foresight is something that the average person rarely sees and is the most important role of all.
Through your camera lens you don’t just capture a visual image, rather you preserve a whole world, one to be studied and hopefully better understood by all.
This article was first published on Dive Photo Guide.
Posted by Dida at 12:16 PM
June 15, 2008
Safe Diving Reminder
Here's a reminder from Steve Clabuesch, Diving Safety Officer at UCSC, about maintaining safe diving protocols--Dida
photo of DK at Point Lobos courtesy Doug VanOmmeran
As everyone begins their work for the Summer it is imperative that every diver remembers that dive safety begins with the individual diver. Diving does have inherent risks and managing those risks is what prevents accidents. Risk management is every diver's and dive supervisor's number one job. And the risks begin above the water in the loading of gear and the use of vehicles, trailers and vessels - make sure you have proper training before driving vehicles, trailering vessels and operating boats.
Common incidents as new divers begin working and more experienced divers become complacent, tend toward poor air and decompression management and pushing the physical limits of one's diving capabilities. Below is a list of practices, that will help prevent diving accidents. I encourage everyone to review this list, and add to it, and share it with their divers. Make sure you have emergency contact information for all your divers at the dive site for every dive. Safety first, data second.
In the event of a suspected diving injury, contact your dive supervisor/leader and DAN (919-684-4326), begin oxygen therapy and prepare transportation to the nearest medical facility. Do not try to self-diagnosis without the help of DAN, they are your best resource to determine your course of treatment (or non-treatment). Make sure your DAN membership and insurance are current. Remember denial = delay = diminished recovery potential.
Prior to diving be healthy, rested and hydrated.
Plan appropriate bottom times based on depth, depth certification and air consumption. And then stick to the plan.
Manage air and decompression conservatively - on the surface with no less than 500psi after each dive, never allow your dive computer time at depth to be less than 10 minutes - especially critical on repetitive dives.
Ensure you are entering the water with an amount of gas that is appropriate for the task as well as a sharing air contingency.
Slow ascents (30 feet/minute) with safety stops of at least 3 minutes if the dive was deeper than 18 feet (longer if dives were strenuous or exceptionally cold).
Use a deep stop for any dive deeper than 60 feet (a deep stop = on ascent, stopping at 1/2 your maximum dive depth for 1 minute, then proceeding to your safety stop).
Take at least a 1 hour surface interval between dives - each diver should know how to use the planning mode on their dive computer to ensure that 1 hour is sufficient.
Stay hydrated throughout the day and stay as warm as possible between dives.
Use proper lifting technique and get help when lifting heavy loads - diving is hard enough on our bodies, don't make it harder.
Log your dives weekly in order to retain their accuracy - the longer you wait, the shorter your memory.
Have a safe and productive field season - now go forth and count!!
Posted by Dida at 9:05 AM
March 15, 2008
Calling AAUS Divers – DFG Needs YOU! (and so does Reef Check California): Results of 2007 DFG Abalone and Urchin Surveys
Ed. note: Greg Holzer's 2006 report on the Fort Ross, CA, abalone and sea urchin survey he participated in can be viewed here. He's back with a 2007 report that includes a detailed cruise report --Dida
by Greg Holzer
Each fall for the past several years, the California Department of Fish and Game (DFG), has conducted red abalone and red sea urchin density surveys at designated sites in northern California. Survey sites range along the Sonoma and Mendocino County coastlines. The 2007 surveys were lead by Dr. Laura Rogers-Bennett and were conducted at Ocean Cove in Sonoma County, as well as Van Damme State Park, Point Arena, and Stornetta Ranch in Mendocino County. The Cruise Report for Arena Point/Stornetta Ranch can be found (here) and makes for compelling reading, but I’d like to stress another aspect here--that of actually getting divers in the water for these surveys and cruises.
The DFG survey teams typically include divers from the Department, Bodega Marine Laboratory (BML), Humboldt State, and other related organizations, as well as volunteer AAUS-certified scientific divers. And as the boat leaves the dock, it’s usually clear that more divers would be a good thing.
For most everyone concerned about the progress of marine life conservation, repopulation efforts, and developments surrounding Marine Protected Areas (MPAs), the effort that goes into the work is recognized, as well as the dedicated people involved. There are a lot of deserving projects though, and so DFG is developing a process in collaboration with Reef Check to recruit qualified divers who are interested in this research. AAUS-certification as a scientific diver is necessary to work from DFG’s boats and facilities, and that carries with it the associated training. However, speaking as one of the volunteer AAUS divers on the cruises the last few years, the rewards and benefits are definitely worth the effort to get and maintain the certification, if you’re interested in the work. Among the benefits:
• Use of research vessels and equipment not available to recreational divers;
• Working with biologists and researchers closely involved with the science needed to better manage our marine fisheries (not to mention being able to pick their brains on a wide array of topics of interest to divers).
• Opportunities to obtain related training and instruction, like small boat operation.
• Access to areas not normally dived.
• The confidence and camaraderie of diving with experienced people, all who share your skills and interests;
• …did I mention all the air you can breathe, even underwater?
• Great food prepared by none other than the DFG Captain and crew…and these guys can cook up some fish! (Or burgers for that matter.)
If all this sounds appealing, and you’re AAUS-certified, DFG would sure like to hear from you, and Dr. Laura Rogers-Bennett would appreciate an email from you about possibly helping with the 2008 abalone and urchin surveys.
So, you’re not yet AAUS certified? Not to worry! There is a great alternative for those who want to begin the training and get involved in scientifically-valuable research that even now is shaping the MLPAs along the California coast. This alternative is Reef Check California (RCCA). If you are an experienced diver you can get involved directly with helping to conserve California’s rocky reefs by becoming a trained and certified Reef Check diver. AAUS certification is not required and RCCA trainings are held in the spring and summer throughout California. As an RCCA diver myself, I can say it’s a very rewarding way to spend some bottom time. In addition, as we did on this trip during the cruise at Stornetta Ranch, Reef Check CA sometimes teams up with DFG to expand the scope of the data gathering. Presently RCCA is working with DFG and others to be able to facilitate AAUS Scientific Diver Certification. Look for updates on the RCCA website. In the meantime, check out the RCCA training page or go to this link to hear from other divers about what it is like to be a RCCA certified diver.
The DFG and Reef Check survey protocols are directly comparable to commonly used sampling methods (see Memorandum of Understanding) and were developed in collaboration with DFG, PISCO and others subtidal research programs to ensure the data collected can be used to improve marine management (see article by C. Dawson published on this site here). Divers lay 30-meter transect tapes, each on a specific heading, then conduct surveys along the transect while completing a datasheet tabulating measurements and quantities of selected species that occur within one meter on each side of the tape. The starting point of each transect is identified with GPS coordinates in the case of DFG abalone transects, and haphazardly placed in the case of RCCA surveys.
DFG survey species include emergent (i.e., large enough to be seen easily with the naked eye) red, flat, and pinto abalone as well as red and purple sea urchins. In addition, selected algal species and certain associated species (e.g., bat stars), as well as notes on seafloor composition are recorded. These species are also surveyed in RCCA surveys. Typically, it takes between 30 and 60 minutes to complete a DFG abalone transect depending on a variety of factors like the number of animals, amount of rugosity, and general sea conditions, which can be challenging in some of the shallower spots with kelp and heavy surge.
The main objective of the surveys at Point Arena Cove and Stornetta Ranch was to assess the density and size frequency distribution of red abalone (Haliotis rufescens) and red sea urchin (Strongylocentrotus franciscanus) populations. However, the task list for research cruises evolves continuously, based on opportunity and other needed research, and every effort is made to maximize the value of the cruise. Additions during this cruise included:
• Taking a small sample of epipodium from 50 red abalone, for genetic research (yes, they were returned “home” with strange tales to tell their friends).
• Collection and examination of 70 small boulders to assess recruitment levels of red abalone.
• Conducting plankton tows to assess levels of larval abalone.
• Conducting fish and related survey transects, in support of ongoing monitoring by RCCA in collaboration with DFG. As mentioned above, some divers aboard were trained in Reef Check protocols and were able to conduct surveys for a wider range of selected invertebrate, algal, and fish species as well as quantifying the type of substrate at this site. The RCCA transects were completed to provide a more comprehensive ecosystem site assessment at this site. Such collaboration is valuable in leveraging the skill sets of the participating groups, make it possible to field more divers, and maximize the value of each cruise. With the compatibility of DFG and RCCA data-gathering procedures and protocols, used together they provide a more complete picture of the overall underwater habitat and communities. These results, in turn, provide a more complete body of scientific evidence needed for creation and management of Marine Protected Areas (MPAs) and assist managers in making sustainable management decisions. (Click here for more information on Reef Check)
During the four days of the cruise we sampled a total of 36 transects at Point Arena Cove, and 33 at Stornetta Ranch, for a total of 69, exceeding considerably our goal of 56 total for the two sites. All the details are available in the Cruise Report (click here).
One particularly interesting aspect of this cruise was surveying abalone at Stornetta Ranch. This site was closed to public access until 2004 when the land was transferred to the state from a private owner. Prior to the public opening an extensive intertidal as well as subtidal survey was conducted to document abalone and urchin densities. The survey completed this year was the first survey of the subtidal area since the public access opening in 2004, and yielded a striking display of the effects of public access on abalone populations (see Cruise Report).
A few other cruise details:
• Again this year, the divers had as their base of operations the DFG’s enforcement vessel P/B Marlin, a 54-foot aluminum catamaran, skippered by Captain Keith Long, with Warden Steve Johnson and Engineer Jeff Rose as crew. The Marlin is equipped with a 17-foot Rigid Hull Inflatable and electric/hydraulic hoist for launching. In addition, BML supplied a 14-ft. Zodiac with a 25-horse motor. The Marlin is a capable and comfortable diving platform, and with this combination of personnel and equipment, we were able to field as many as five dive teams each day to lay and survey sixty-nine, 30-meter transects during four days of diving operations. The Department also provided a portable compressor so that empty tanks could be filled during diving operations, minimizing the number of tanks that had to be handled, and preventing the need to load and unload tanks during the cruise. Incidentally, support for the dive teams comes from the department’s Wildlife protection patrol boats, captains, and mates. Funding for many of the surveys is made possible by the recreational abalone fishing stamp funds.
• As is common, we had some mechanical problems to overcome, and some divers were limited by illness, so the schedule necessarily varied each day with status of the divers, equipment, and the research efforts.
• Water temperatures for this cruise were in the low to mid 50 Fº range, and visibility varied from less than five feet in shallow, turbulent areas, to near 40 feet on some deeper transects. Overall sea conditions were essentially flat for the entire week, making for some very enjoyable diving.
All in all, as one of the volunteer AAUS scientific divers, it was a very rewarding trip, and I encourage anyone who shares these interests to touch base with Dr. Rogers-Bennett (email). If this year is similar to the last few, trips will be scheduled periodically from mid-August through late October 2008. I hope to see some new faces this year!
Posted by Dida at 1:10 PM
September 7, 2007
Shark Activity Protocol
UC Santa Cruz' Diving Control Board has announced it's OK to resume diving in the Monterey and Pacific Grove areas after just one day of prohibiton. However, they advise that divers not work in areas for at least a week after the last reported shark activity. Admitting that great whites are often present in these waters, and one of the hazards of working here, they have come up with the following protocol in case you ARE diving in a suspect area:
Shark Activity Protocol
- All dive plans must be pre-approved by the DSO prior to departure - this can be done by email or verbally. You will need to provide days and location of operations, members of team, shore contact and planned operations.
- All divers, boat operators and shore contacts need to be made aware of the inherent hazards associated with the operation during times of shark activity and be especially attentive to surroundings during the operations. Shore contacts need to be able to be contacted at anytime during the hours of operations, no exceptions. All vessels need to have at least two means of communicating with the shore contact.
- All boat operations need to have a person on the boat at all times that can render immediate aid (bringing an injured diver into the boat and providing first aid) and be able operate all aspects of the vessel. An efficient method of coming aboard the vessel in an emergency needs to be discussed prior to departure. A first aid kit needs to be aboard the vessel. Diver recall strategies also need to be discussed.
- Surface swimming should be minimized, know compass headings back to the anchor line and as a backup, to shore. If the situation dictates a direct ascent to the surface, do not make a safety stop but do ascend as slow as you can but as fast as you need to with your buddy. Be prepared to enter the vessel as quickly as possible, ditching BC and weight belt if necessary.
- Buddy teams need to stay within touching distance at all times, especially on the surface. This "safety in numbers" statistically proves to be effective when reviewing shark attacks on SCUBA divers.
- Upon arrival at your work site, if there is evidence of shark activity you must cancel the dive and notify your shore contact and DSP office of your findings ASAP.
- Each diver needs to assess the risk of each dive and make their own decision as to their ability to safely complete the assigned dive. Any diver may refuse to make a dive, even if their decision will lead to the cancellation of the day's activities.
- Divers swimming through the water column from point 'A' to point 'B' should have at least one "safety sausage" for each buddy team. If you cannot continue your swim due to a shark sighting, deploy the float to let the boat driver know you need to be picked up. Do not ascend
until the boat is overhead and you deem it safe to do so.
- Boat anchoring systems should be set-up so that in an emergency the entire anchor rode can be thrown overboard or the anchor line can be cut very quickly so as not to delay a response to an emergency.
- All anchoring should be done well within a kelp bed and not out in open water.
- A signalling protocol should be established so that divers know if the boat is dealing with an emergency and what they should do - come back to the boat underwater if it is safe or stay where you are and deploy your float, the boat is coming to pick you up.
Posted by Dida at 5:41 PM