This morning at low tide we came across several pacific sand lance on the beach. They had just spawned and lay dead on the beach awaiting the predators.
It is especially important through July and August, (note last year)when they are spawning regularly to avoid heavy traffic on the beach (especially horses).
The holes punched out by horses can be up to 25 cm. in depth.
The Metchosin Community has a considerable population of recreational horses. It is accepted that to criticize anything horse-related might not be politically correct in Metchosin.
The pictures included in this post represent an extreme example but they are useful in order to point out the potential environmental impact of this activity. Let alone making it difficult to walk on until the next high tide comes in to smooth it out, the real issue is what is happening to the habitat of the forage fish. Both Pacific Smelt and Sand lance inhabit intertidal zones on Taylor beach. When they spawn, these forage fish deposit eggs just under the surface of the sand . They are vulnerabale to compaction and excessive drying out before they are carried out by the tide. Given the lack of protection afforded the habitat of these fish and the over-harvesting in the herring fishery, these essential small fish of the food web are challenged enough already.
Horse hoof punctures in the sand right down in the area where sand lance are depositing their eggs in burrows.
Sand lance and ruler in centimetres
Sandbar at the North end of Taylor Beach
This morning with the extreme low tide, (tonight is the full moon) the small sandbar off the north end of Taylor beach was exposed for a few hours. As the tide came back in, a crow and a glaucous winged-gull were patrolling the area and picking up sandlance as they emerged from the sand, flipped around a few times and then died. In 15 minutes walking back and forth along the 40 metre stretch of the sandbar, I picked up 15 of the dead sandlance, forage fish. Several that were still active were returned to the water where they died within a few minutes. Perhaps this a solution– having direct predation as soon as they emerge from their sand burrows in order to prevent fouling of the beach..
Species recognized by IRMNG:
Kingdom: Animalia +
Class : Actinopterygii
Genus: Ammodytes Linnaeus, 1758
See this post on Sandlance on Taylor Beach:
Image from the presentation below
One of the unusual characteristics of sandlance on Taylor Beach is that in less thsn a minute after emerging from the sand after spawning, If they are not consumed by crows or gulls, then they will die. ( so far I have not found this reported in the literature?)
|Family: Trachinoidea (Bonaparte, 1832)
|Species: A. hexapteris
|Binomial name Ammodytes hexapterus
This presentation by Ramona de Graaf and Dan Pentilla provides a good background on the importance of habitat for Forage Fish on our shores.