Baja California Wetlands

BAJA WORKING GROUP – CLIMATE SCIENCE ALLIANCE

Baja California Wetlands Drew Talley (University of San Diego)

A VIEW OF ONE OF THE LARGEST INTACT SALT MARSH SYSTEMS, FOUND IN BAHÍA DE SAN QUINTÍN, BAJA CALIFORNIA. PHOTO CREDIT: DREW TALLEY

Key Takeaways •

Sea lev­el rise and warm­ing tem­per­a­tures threat­en salt marsh­es in the Cal­i­for­nias.

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Es­tab­lish­ing long-term mon­i­tor­ing and lever­ag­ing his­tor­i­cal re­search will al­low us to bet­ter pre­ dict and man­age cli­mate change im­pacts.

www.climatesciencealliance.org/2021-baja-report

What is the focus of your research? With nu­mer­ous col­lab­o­ra­tors over the last 25 years, in­clud­ing the Ensenada Center for Scientific Research and Higher Education, Ter­ra Penin­sular, Cal­i­for­nia State Uni­ver­si­ty at Long Beach, and Scripps In­sti­tu­tion of Oceanog­ra­phy, I have ex­am­ined the food webs of salt marsh­es in the Cal­i­for­nias, from San Fran­cis­co Bay to Bahía de San Quin­tín and the up­per Gulf of Cal­i­for­nia. A ma­jor fo­cus of our work has been un­der­ stand­ing habi­tat con­nec­tiv­i­ty (in par­tic­u­lar, but not lim­it­ed to, spa­tial sub­sidy), and how hu­man im­pacts can act to dis­rupt nat­ur­al lev­els of connectivity.

How do you see cli­mate change im­pact­ing the fo­cus of your re­search? Prob­a­bly the most press­ing is­sues out­side of di­rect hu­man ac­tiv­it­ ies (e.g., habitat loss and destruction) are sea lev­el rise (SLR) and warm­ing temperatures. With so many wet­lands al­ready lost, and those that re­main of­ten con­strained at the up­land mar­gin by man-made struc­tures, wet­lands have lit­tle room to mi­grate with SLR. Fur­ther, warm­ing temperatures can lead to a shift in the community from temperate species to more tropical ones.

What cli­mate im­pacts are you see­ing? We are al­ready see­ing taxa with south­ern affini­ties be­com­ing more com­mon in our wet­lands, and that trend will un­doubt­ed­ly con­tin­ue, with warmer-wa­ter species becoming per­ma­nent­ly es­tab­lished fol­low­ ing El Niño events. Fur­ther, SLR is cre­at­ing erosion of bar­ri­er beach­es pro­tect­ing some wet­lands, and gen­er­al­ly con­vert­ing wet­lands to more deep-wa­ter habi­tat.

What are you most con­cerned about? As men­tioned by oth­er Baja Working Group sci­en­tists, longterm mon­i­tor­ing is crit­i­cal for teas­ing apart nat­ur­al from an­thro­pogenic changes to nat­ur­al sys­tems. Yet this sort of work can be dif­fi­cult to fund, and suf­fers a mis­per­cep­tion in some aca­d­em ­ i­c cir­cles that it is “not real re­search.”

THE CALIFORNIA KILLIFISH, FUNDULUS PARVIPINNIS - A NATIVE FISH THAT IS AN IMPORTANT FOOD WEB LINKAGE IN WETLANDS OF THE CALIFORNIAS. PHOTO CREDIT: DREW TALLEY

What are the gaps in understanding that need more re­search? Wet­lands are of­ten viewed in iso­la­tion of their land­scape and com­po­nent habi­tats. Un­der­stand­ing the retic­u­late in­ter­con­nec­tions among and across habi­tats (e.g., seagrass beds, un­veg­e­tat­ed flats, up­land habi­tats) is crit­i­cal for un­der­stand­ing, man­ag­ing, and restor­ing wet­lands. Even ba­sic nat­ur­al his­to­ry of many wet­land inhabitants are sorely lack­ing.

What is your plan mov­ing for­ward to start to bet­ter un­der­stand or min­i­mize the im­pacts from cli­mate change? Crit­i­cal to pro­tect­ing these coastal tran­si­tion zones is bet­ter un­der­stand­ing the nat­ur­al dy­nam­ics, and en­gag­ing stake­hold­ers (pub­lic, man­agers, in­dus­try) that use and af­fect these habi­tats. Re­vis­it­ing pre­vi­ous stud­ies [e.g., (1–3)] while en­gag­ing the pub­lic in mon­i­tor­ing pro­grams is a pow­erful first step to­wards im­ prov­ing our un­der­stand­ing and our abil­i­ty to pre­dict fu­ture climate im­pacts. Es­tab­lish­ing stan­dard­ized mon­i­tor­ing pro­grams is crit­i­cal to these ef­forts. We should also work to lever­age ex­ist­ing his­tor­i­ cal re­search, much of which is buried in “grey lit­er­a­ture” such as grad­u­ate stu­dent the­ses and gov­ern­ment re­ports. Re-sur­veying these his­tor­ic­ al stud­ies can pro­vide some in­sight into long-term changes in these threat­ened ecosys­tems.

ABRONIA MARÍTIMA EN LAS DUNAS DEL SOCORRO EN BAHÍA DE SAN QUINTÍN, BAJA CALIFORNIA. AUTOR: DREW TALLEY

References 1. Macdonald, K. B. (1969). Quantitative Studies of Salt Marsh Mollusc Faunas from the North American Pacific Coast. Ecological Monographs, 39(1), 33–60. https://doi.org/10.2307/1948564 2. Griffis, R. B., & Chavez, F. L. (1988). Effects of sediment type on burrows of Callianassa californiensis Dana and C. gigas Dana. Journal of Experimental Marine Biology and Ecology, 117(3), 239–253. https://doi. org/10.1016/0022-0981(88)90060-3 3. Talley, D. M. (2000). The Role of Resident Fishes in Linking Habitats of a Southern California Salt Marsh [UC San Diego: California Sea Grant College Program]. https://escholarship.org/uc/item/1qr663x4

www.climatesciencealliance.org/2021-baja-report