One of my most vivid childhood memories is of a field trip our class took when I was in the fourth grade. We went to the beach near Fort Casey on the west side of Whidbey Island during a very low tide to explore the tide pools the low water revealed. I have the images from those pools deeply and indelibly etched in my mind: the octopus that one of the teachers discovered, the sea cucumbers, the crabs. It is as clear to me today as it was 30 years ago. One of my first acts upon returning to Whidbey Island was to
get a tide chart. If you want to clam or crab, or if you want to know when you will be able to launch your kayak from the beach and not have to wade through mud, it is necessity to have one. It will also tell you when the currents will be particularly strong, and therefore when being out on the water in a kayak with a young child is not advisable. I was very pleased to discover some very low minus tides in the month of July, and I thought immediately about reliving some of that tide pool exploration at Fort Casey.
A minus tide means that when the water is at its lowest level it will be below the mean low tide level. The numbers used to describe this are in feet, either above or below the mean. Above the mean is expressed as a positive number, but if the water level will be below the mean, it is expressed as a negative number: a minus tide. Tides that fall below the mean are not rare, but really low tides, say three or more feet below the mean, only occur in our area a few days each year. In addition there is an equal chance that they will occur, as they did in January of 2009, in the middle of the night.
So I was very pleased that in July we had four days in a row of minus tides of -3 feet or more, all occurring in the middle of the day. A true treat. Bare in mind that each foot of negative water level is a vertical foot of water, and so if the beach is slanted at a fairly shallow angle, three feet of water level can reveal 5 to 20 feet of what would be the sea floor all but a few hours each year. So with our rock collecting bags in had, Tyla, Maggie Rose, Molly and I headed out to explore what the -3.5 foot tide of July 21st would reveal.
Probably the greatest gift that children give us is their fresh view of our world through their sharp, young eyes. Maggie Rose has always been a huge fan of nature, and her sister Molly is a big fan of worms and bugs and now baby crabs. She will fearlessly handle the little pinchers and even if they giver her a little nip, she goes right back for more. The first part of our walk to the pools from the main parking area of Fort Casey was along the round wave washed stones and pebbles that make up many of the beaches on Whidbey Island. This is great for a rock hound like Maggie Rose, and hell for her mother and father who invariably end up toting back the stones.
As we headed further up towards the point that lies between Fort Casey and Camp Casey, we saw lots of gulls searching the exposed beach for lunch. Baby crabs and other critters that use the shallows and the kelp forests for shelter against larger fish that live in deeper water, but are vulnerable to birds during low tides like this. At the point, a large growth of kelp was visible, along with several large rocks which only protrude from the Sound at such low tides. This was our target area of exploration. This growth of kelp provides a buffer for what is essentially an aquatic nursery for all varieties of baby fish, mollusks and arthropods. Once we got out to large rock, and saw how crusted it was with life, we knew we had come to the right place.
While I have sung the praises of my daughters sharp eyes, I have to say that my wife, Tyla, spotted and was able to nab some impossibly small critters. She got tiny hermit crabs, snails and what has to be the smallest Dungeness crab it is possible to see. The crab was literally the size of a tick, and you can really see the family resemblance at that scale.
I hope you will enjoy the photo gallery attached as much as we enjoyed our adventure.
For more inforation on Fort Casey you may try the following link.
For more information on the action of tides, you may try this link.