Anchoring and eelgrass

D

Doryman

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JamesTXSD":3dtt7yah said:
It was a big cruising day today - just over 3 miles from Roche Harbor to Garrison Bay; light years off difference in attitude, though. Garrison Bay is a relatively shallow anchorage with room for plenty of boats. Nice protection, and we took advantage of our shallow draft to work our way all the way in; dropped anchor in less than 8 feet of water in the lee of a small island. The wind was blowing about 12-15 and the water is very calm here.
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The above quote is from a Wild Blue post. I am posting it not to dump on Jim but to start a discussion about eelgrass. From what I have read, eelgrass is a critical component of the marine ecosystem. It provides habitat for herring eggs, and a bunch of other good things I have forgotten.

From what I understand, eelgrass grows in waters up to about 25 feet in depth. We are encouraged to avoid anchoring in waters shallower than that so as to spare the eelgrass. Reason: when an anchor drops, it drags and tears out eelgrass. Also when the boat swings, that also damages it. Multiply by the number of boats that visit a popular anchorage and you are talking about a lot of damage.

That is the argument, from an article in a recent publication (might have been Norwesting.)

I am curious what the prevailing Brat-sentiment about this is.

Warren
 
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Best anchor for holding in eelgrass?
 
Same problem in Georgian Bay, Canada. especially coming through the Trent Severn Canal. You have to anchor in grass, because it's all shallow and all grass, and "they" don't allow cutting or spraying. It's a real hard time getting a good set, but the Bruce does a good job. But then, you're not supposed to destroy fish habitat.

Soon, the recommendation will be not to anchor, but just go out for the day. Or marina hop, until they get choked out.
Boris
 
Hi Warren, ol' buddy,

Dump away! :wink I don't believe there is any eel-grass beneath us right now. I use the sounder each time we anchor to check the bottom - not just the depth, but the contour and bottom surface. A grassy bottom is pretty easy to determine with the sounder, and something that I'd just as soon NOT anchor in. I'm all for saving the planet, but I also want a good night sleep at anchor... and I get a better set in mud/sand than grass. 8)

Another advantage of a shallower anchorage is that you can often see the bottom. Joan is on the bow, checking it out before we drop the anchor. Most of the time around here, we have to rely on the sounder. In other places we've cruised, we will put the bow over a good sandy spot that we can see, and settle in.

In Florida, the sea grass is protected, like the coral. In one crowded anchorage, there was concern that we were going to "touch" the sea grass with our hull. Hell, we draw a foot with the motor up... that would concern me, too!

We'll set more than one anchor to keep us where we want to be. Anchoring is a part of cruising. Actually a protected part of "navigation" with all the furor in Florida about cities not allowing boats traveling through to anchor. We don't want to mess up the environment, nor nuke the whales... shucks, I even quit eating spotted owl. :twisted: It's my belief that we impact the bottom less by selecting a decent place to anchor as opposed to just plunking it down any ol' place.

Best wishes, :hug
Jim

PS - I was going to talk to you about all those hydrocarbons you're putting into the ozone with those two big motors on the back of that TomCat. :mrgreen:
 
Warren

Ranks very low if at all on my to be concerned or to avoid list. Maybe it would be different if our boating was done more in the San Juan or lower inland passage areas. Always have gone for the shallowest and closest to shore possible when anchoring. In most of these places the seals and other wild life intend to act like the boat is something entirely new in there life, so in our case I doubt if the impact amounts to anything worth being concerned about.

Our reasons for owning a boat and how we use it may be somewhat different then many on this site. We get absolutely nothing out of being out on the ocean with nothing to see, but water all around and fishing ranks very low on our things to do. What we do enjoy is being very close to shore whether on the cruise or at anchorage and that preverably with no other boats or at least very few around.

Jay
 
Any of the sea grasses are important in the nursery of fish. We have deminishing sea grasses in the Gulf area. Another factor, as well as prop scaring and anchor dragging, is the increased turbidity from tug and barge traffic. The nursery sea grasses (and I lump a number of varius species here) are generally in shallow water, because of the penetration of light--which is necessary for the growth of these type of grasses.

We do not anchor in grasses if at all possaible. There are often bare patches and you can put the anchor there, and set it. There are lots of options--at least for us on the Gulf coast, since the anchorages are not crowded--go to another anchorage, put the boat on the beach (consider what the tides are going to do, and be sure you can float off when the time is to leave).

In some parts of the World we have actully dove on the anchor, cut a small section of sea grass, and then started the anchor's penetration, so that minimal grass would be distrubed.

In some marine sanctuary areas, anchoring is not allowed because of the damage to the grasses and benthos--moorings are provided.
 
I forgot to mention in my original post that Cap Sante Marina here in Anacortes is undergoing a massive reconstruction project, and part of that has involved mitigation of lost eelgrass -- I read in the paper about how they are planting (by hand) eelgrass nearby. You can read about the project HERE.

As a secondary point of interest, if you are curious about the demographics of the boating population there is a big file of powerpoint slides ( C-F Moorage Configuration Studies ) that you can look at.

Warren
 
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