Please respond-email me when the time permits.

Thanks,
David Steven Brown

Nick, Thank you in advance for forwarding to Dr. Ravit.

This is an important part that landscape architects can play, since we are often called upon to develop plans for restoration of sites along our coastlines.

Sincerely,
Aris
Aris W. Stalis, ASLA, LEED AP

Thank you for sending this article on to me. There are a couple comments I
will make, but keep in mind my oyster experience is solely within the
Hudson-Raritan Estuary (HRE), a very unique place!

1. The writer assumes that oyster larvae are in the water in abundances
that allow enough juveniles to set on the introduced substrate and survive
their first year to produce a viable new population. We have not seen this
to be the case in the HRE, and we believe the dearth of larvae is due to
the fact that the adult oysters are all but “ecologicall extinct” in the
HRE system. Without adults spawning to produce viable larvae, there will
be no set or a set that is too small to survive (high first year mortality
is typical). I should note that in southern NJ waters this approach does
seem to be producing viable sets.

2. The project described was built in a warmer climate than NY/NJ and
north of the HRE experiences. We have found that the survival rate under
the intertidal conditions described (the oysters are exposed to the air
during low tide) is terrible in the HRE. Our test oysters had much higher
survival rates when they remained under water continually (subtidal). This
positioning also allows the oysters to filter continuously, thus
contributing greater water quality benefits. However, a subtidal placement
is harder for a non-diving volunteer to monitor.

3. Just placing bags of shell does not take into account the hydrology of
a site. If there is strong energy due to currents, wind, or waves then the
oysters may require some additional support to withstand natural forces.
If the restored oysters do not have proper support, they will be washed
away.

4. Please note that the calculations of how much an oyster filters are
typically done under lab conditions. In my opinion, these estimates should
be considered “potential” filtering activity. It is notoriously difficult
to measure actual water quality benefits in the “real world” since the
systems we are typically dealing with are quite massive. Some scientists
have tried various methods to measure effects on water quality in the
field, but actual field data attributable solely to oysters is hard to
get.

5. Although one parasite is mentioned (MSX), there are other factors that
can affect the oysters’ health and survival. Another common pathogen is
called dermo – we have seen evidence of both MSX and dermo infection in
HRE oysters. We have also seen adverse tissue effects which we believe to
be the result of environmental contamination. Until waters at a
restoration location are deemed clean enough (what is “enough”?) for
oysters to survive (they are susceptible to pollution, the marine “canary
in the coal mine”) we should be pre-testing sites to make sure that we are
not building a restoration doomed to longer-term failure.

Having said all of the above, based on our initial results in Keyport
Harbor, I enthusiastically endorse identifying as many appropriate sites
for oyster restoration in the HRE as possible. Eastern oysters contribute
habitat that is valuable for other species, and if we can reach critical
masses, the water quality and shoreline protection aspects could be
significant.

Beth

Beth Ravit, PhD
Department of Environmental Sciences
School of Environmental & Biological Sciences
Rutgers University
14 College Farm Road
New Brunswick, NJ 08901
P: 732-932-9800,ext 6210