The Natural History of Bodega Head

Tuesday, July 16, 2019

A few more tips

Black-tipped Spiny Dorid (Acanthodoris rhodoceras), 16 July 2019. We've seen a few individuals of this nudibranch recently, all with this very dark coloration. Note the two long rhinophores tipped with reddish-brown, and the prominent gill plume (it looks a bit like a flower). There are also nice gold highlights along the edge of the mantle. Thanks to Eric for spotting it!

P.S. Interestingly, when we were seeing this species several years ago (in 2015), most of the individuals we found were much paler. For an example (with video), see the post called "A few tips" on 6 June 2015.

Monday, July 15, 2019

Pretty cool (or not)

Bands of fog and light on 14 July 2019.

Remember the mussel die-off I posted about on 18 June 2019? Well, ever since then I've been wondering (and lots of people have been asking) about how unusual the air temperatures were in early June.

If you live near Bodega Bay or have visited, you know that it is a pretty cool place (literally). My impression was that the hot temperatures in early June 2019 were rare, and there were other signs pointing to that because there were record-breaking air temperatures throughout the Bay Area for those dates. But I hadn't seen an analysis of air temperatures at the coast in Bodega Bay. I've been busy during the last few weeks, but this past weekend I finally had a chance to review some local air temperatures. I found the results interesting, so I'll share some below.

This is based on air temperature records from the Bodega Marine Laboratory for the last 10 years (2008—2018). (Air temperatures vary depending on where they are taken; these are from a sensor adjacent to the Bodega Marine Lab on Bodega Head.) Note also that these are first-cut calculations, but I think they'll help provide some perspective about air temperatures in Bodega Bay.

Below I'll pose some questions so you can ponder the answers, and then I'll provide the answers after the questions.

(A) In Bodega Bay, during the last 10 years (2008—2018), on how many days did the air temperature reach over 80°F? Answer: Two.

(B) In Bodega Bay, during the last 10 years, on how many days did the air temperature reach over 75°F? Answer: Four.

(C) Of the days over 75°F, how many were in April-May-June? Answer: One.

(D) In Bodega Bay, during the last 10 years, on how many days did the air temperature reach over 70°F? Answer: Thirty-seven.

(E) Of the days over 70°F, how many were in April-May-June? Answer: Six.

(F) And of those days over 70°F in April-May-June, how many were in June? Answer: Zero.

(G) In Bodega Bay, during the last 10 years in April-May-June, how many times has there been a period of at least two consecutive days with air temperatures that reached over 70°F? Answer: Zero. The episode on 10-11 June 2019 appears to have been the first time during 2008—2019.