Dive_Blog_2024_10_10_SSS1
Purpose: Watching El Nino Underwater TLC and sensor recovery and deployment.
October 10, 2024
By: William Hagey
Point Loma – SSS1
Vessels: The Celtic Knot
Topside Support: None
Divers: William Hagey, Paul Rahilly, and Jim Melrod.
Surface conditions: 1 to 2 foot swell but not choppy, sun burning through overcast.
Visibility: 25 ft with some swell beginning to stir things on the bottom
Temperature: 54° F
Current: Very mild. (Gee but it is great to have the kelp back to reduce the current!)
Dive: Time in: 12:57 pm, Dive length 41 minutes
Depth max: 58 ft
Purpose: Deploy and Recover TLCs – and do a video transect.
Summary: There is even more Macrocystis (kelp) and it is looking more mature and thicker. We swapped out the TLCs, did a video transect, shot video and took stills.
Equipment Notes: TLC NOAA3 with MintDOT913:230 were recovered. Both collected full sets of images and data. The battery for the UVC LED and the salve LED light was 14.8V at 5AH made with two batteries that were diode-OR’d together. The UV-C light aimed at its window with a duty cycle of 30 seconds every 6 hours. The window on the camera was free of biofouling; the UV-C light seems to be working for this. (The replacement UV-C light had it’s aluminum parts encapsulated in urethane, WC-575.
Here’s a link to the time-lapse video:
Habitat characteristics and surveys:
The kelp bed is back again here, but why? This site has gone through dramatic changes in the past few months! It is looking more like it did a couple of years ago. I have now seen this site go from a mature macrocystis kelp forest back in 2014 when we first discovered it, to a wasteland after the 2015/16 El Nino event, to a place where the kelp came back, then to a gost town again, and now back to a kelp bed again. Maybe with our work in this project we will get a better insight into this.
At this point there is plenty of upper and lower story algae,macrocystis and pelagophycus (elk kelp). There is also a lot of lower story brown and leafy red algae too, including Laminaria and Desmarestia. W Hagey got video with his GoPro and Jim took stills.
here:
Methods: I believe we have a good anti fouling solution with the UV-C lights going on for 30 seconds every 12 hours. We increased the rate to every 6 hours because we have the battery life, but I don’t think we need it this often.
Abalone: We have up close, too close, time-lapse images of a large red abalone. I also saw some adult reds in the wreckage and fed one of them and video recorded it.
Dive Details: We used the coordinates and landed about 8 meters northeast of the wreckage. We found it quickly and we continued in that same direction to find the TLC 50 meters away from the anchor, so this turned out to be a good video transect.
This is the Oxygen and temperature log for this deployment.
These three images are samples from the past three deployments. The bottom image is from the most recent deployment. We are working on aiming the cameras the same between deployments. The middle one was aimed a little lower than ideal.
Notice how the abalone is lifted pretty high off the rock. This is its “ready to capture drift kelp mode” in the image from the last deployment. It is not exactly a “pounce”, but somehow, in a trick that I don’t understand, they are able to grab kelp as it drifts by. Just imagine trying to do this, without fingers, arms or even jaws!
