SEA OTTERS AND DETRITUS AND EVERYTHING ELSE

Sea Otters are known as a keystone species.  This simply means that like the keystone in an arch once removed the entire structure will collapse. In the case of the Sea Otter it is often simplified by saying the otters eat herbivores (sea urchins, snails, chitons, limpets) that feed on kelp thus protecting the kelp beds from being overgrazed which would lead to the destruction of habitat and food resources for many marine species......basically without the otters the very productive and diverse world of the kelp forest would disappear.  This has been documented in the real world.

So let's follow the energy flow in the kelp forest and see just what might be a stake here.

KELP FOREST ENERGY FLOW (PACIFIC COAST N. AMERICA):

                                                    (Energy flows from 1 to 7)

1. SUNLIGHT (AND NUTRIENTS) 

2. KELP and other Seaweeds (mostly large brown seaweeds)

3. KELP DETRITUS (small bits of dead kelp WITH BACTERIA)

4. DETRITIVORES (GAMMARID AMPHIPODS, ISOPODS, OTHER SMALL CRUSTACEANS)

5. 45 SPECIES of INSHORE  AND MIGRATORY FISHES THAT FEED ON DETRITIVORES

6. FISH EATING FISHES, RIVER OTTERS, SEALS, SEA LIONS, DOLPHINS, PORPOISES,

    BALEEN WHALES, VARIOUS SEA BIRDS, BALD EAGLES, OSPREY 

7. KILLER WHALES (ORCA) 

The key to the entire ecosystem is, of course, KELP.  In the natural world of shallow water Pacific coast of N. America the major organism tasked with controlling the populations of kelp eating herbivores is the SEA OTTER.

NOTE:  While other predators (Sea Stars, snails, crabs) also prey on the herbivores they have not demonstrated the ability to keep the herbivore populations in check to protect the kelp beds in the absence of the Sea Otter.  

Kelp dying

Kelp

Kelp

Bull Kelp

Kelp

Kelp eating Sea Urchins

Chiton - kelp eating

Kelp eating limpet

Kelp Crab

                                     

Sea Otter

Gunnel - eats amphipods

Sculpin - eats amphipods

Clingfish - eats amphipods

Flounder - eats amphipods

                                   

Juv. Salmon - eats amphipods

River Otter - eats fish

Great Blue Heron

Bald Eagle

Cormorant

Gull

Osprey

Alcids

Terns

Puffin

CA Sea Lions

Dall's Porpoise

Harbor Seal

 

Killer Whale

                                   

SEA STAR WASTING UPDATE 5-5-15

A survey was done on May 5th 2015 at Constellation Marine Reserve in West Seattle for Pisaster o. (Purple Star).  The survey was restricted to the breakwater just south of the park boundary and included only the south side of the breakwater.  A check of the pipeline rip-rap at the park's south boundary was also done at the minus 1ft. tide level.  On the breakwater 38 Pisaster o. were counted and all appeared healthy.  Although actual measurements were not taken all of the sea stars appeared to be approximately the same size (size of a normal human hand), so may have been all from the same age class.  Two Pisaster o. were observed on the pipeline riprap and both appeared healthy and the same size as the ones on the breakwater.
A report by divers (names not available) was forwarded to me by Laura James (a professional diver, videographer and photographer) stated that they had observed 100 or so Pisaster o. in deeper water on the pipeline over the last few weeks and they appeared to be healthy and adult size.
This is good news for Constellation Marine Reserve as it is the fist time in 2 years that a survey has been completed without finding evidence of SSWD in Pisaster o.  observed.  This summer will tell us more about the state of the Purple Stars at CMR....hopefully we will see an increase in healthy stars......fingers crossed.
Additionally there were 15 Keyhole Limpets seen on the south side of the breakwater which is a rather high number as per my recollection from past years.  These limpets may be benefiting from the low number of the Purple Stars which are a predator of the limpets. 

Pisaster o.

South side of breakwater CMR area

Keyhole Limpets on breakwater

Rip-Rap on pipeline CMR   minus 1ft. tide

Spring Showers over Elliott Bay

Crab Attack and Dying Seaweed

 

 

April 22nd and the Kelp growing in the lower intertidal at Constellation Marine Reserve is already dying.  Brown seaweeds do not tolerate the hot sun and bright sunlight.  So if you are a Kelp you want to attach to something that will keep you in deeper water and not allow you to be exposed to the harsh elements......that is if you want to stay alive.

Some images attached of dying seaweeds and also an image and short video of a Red Rock Crab attacking and eating a Northern Kelp Crab......what with the harsh elements and hungry predators it's a wonder anything survives.   :)

 

Dying Witches' Hair seaweed



Dying Kelp

Dying Kelp

Dying Kelp

Red Rock Crab eating Northern Kelp Crab
 

Red Rock Crab eating Northern Kelp Crab




 

 



Sea Star Wasting Disease Update

 

 

 

A survey of Constellation Marine Reserve in West Seattle on April 20th 2015 results:

 

Pisaster ochraceus (Purple Sea Star)   41 healthy - 5 with SSWD

Pycnopodia helianthoides  (Sunflower Star)   1 small (damaged likely by gull) otherwise healthy

Evasterias troschelii (Mottled Star) None observed

No other sea stars observed.

 

Tide Level:   minus 1.7ft  at 12:45PM

Surface temp:   63 deg f.

Wind - N, light

Clear and sunny

The count included all of Constellation Marine Reserve down to the minus 1.7ft tide level.

 

Much of the beach was covered with an extensive growth of seaweeds, especially Wire Weed and various kelps.  So some sea stars may not have been visible.  The survey only included sea stars that were easily visible without turning over seaweeds or rocks.  Previous surveys have been done in the same manner.  Last year appeared to be a good year for sea star recruitment and many were seen over the Winter and most appeared healthy.  In Spring the juvenile stars go into hiding under rocks and crevasses where they cannot be seen so it is difficult to access the population of juvenile stars during the Spring and Summer.  The question is:  Will these juvenile stars remain healthy or contract SSWD?  We will likely not know the full answer to that for a few years.  All of the Purple Stars observed on April 20th were medium to large size as in the images.

 

The highest count of Pisaster ochraceus  at Constellation Marine Reserve was in August of 2011   -  609  (prior to SSWD). 

 

Sunflower Star (small) with damage (likely due to gull)

Purple Sea Star with SSWD

Purple Sea Star (healthy appearing)

 

 

 

 



April 2015 Snow and Sea Lions

April brings the first good minus daytime tides of the season.  Beach Naturalists training on Sunday the 19th will see only a modest -1.3 ft low tide at noon.  In fact 2015 is not a great year for exceptionally low tides.  The lowest this Summer being only a minus 2.8 ft in Seattle.  Some exceptional years see a minus 4.1 ft low....not this year.  With the low tides during the day we will have a chance to access the status of sea star wasting disease on our local population of stars.  Last year saw a continued decline in the sea star population along the Pacific Coast. Some areas saw considerable numbers of juvenile stars most of which seemed healthy and it will be interesting to see if these youngsters remain disease free and begin the recovery of sea star populations.

Washington State snow pack from this winter is well below average by as much as 70% in some areas of the Cascades and Olympics.  Some late snow in mid April has helped a little but near term temperatures are headed up with 70 deg. the weekend of the 19th.  Spring rains thus far have helped fill Washington's reservoirs and it appears that a water shortage is not likely for Western Washington.  California on the other hand is still in the grip of a multi-year drought and forecasts are not looking good for an ending any time soon.

The April jump in California Sea Lion population in Puget Sound has arrived with more animals being seen in Elliott Bay now than during the winter months.  By mid May most will have left for breeding grounds south.

The North Cascade Highway and Chinook Pass in the Cascades opened earlier than usual this year due to the low snow pack.  This gave us an opportunity to check out the snow pack for ourselves and do a little bird watching.....and feeding.  We observed that Clark's Nutcrackers dominate the Gray Jays when it comes to grabbing food from a willing hand.  Clark's Nutcracker is a resident of the mountain west, while the Gray Jay ranges much farther north into Alaska and northern Canada and is only seen in the U.S. in the western mountains.

CA. and Steller Sea Lions Elliott Bay

CA and Steller Sea Lions Elliott Bay

Washington Pass Overlook

Moving the snow mover

Clark's Nutcracker

Bold Clark's Nutcracker

Clark's Nutcracker

Watch the birdie

Clark's Nutcracker

Gray Jay