Anomalous poleward advection facilitates episodic range expansions of pelagic red crabs in the eastern North Pacific

Abstract

The episodic stranding of millions of pelagic red crabs (Pleuroncodes planipes) along California beaches is a striking and puzzling phenomenon. Pleuroncodes planipes are usually abundant off Baja California, Mexico, and their appearance in central California is thought to coincide with anomalously warm waters and northward advection related to El Niño. This anecdotal association has stimulated many hypotheses, but no hypothesis has gained clear and convincing support. Motivated by an unprecedented number of P. planipes strandings and at-sea observations in 2015-2019, we compiled 10 P. planipes datasets spanning 1950-2019, tested the anomalous advection hypothesis using a transport analysis from 1981 to 2010, and explored other compelling hypotheses. We found P. planipes presence off central California was related to anomalous advection of waters from Mexico, sometimes but not always associated with El Niño events, with P. planipes likely remaining residents of northern waters for several years without additional anomalous transport but potentially facilitated by warm waters. By identifying a mechanism behind episodic P. planipes range expansions, we show that a source water index could provide an early indicator for anomalous events in the future.

Flexible use of a dynamic energy landscape buffers a marine predator against extreme climate variability

“…For example, while we use equations to estimate energy intake based on laboratory experiments in which juvenile tuna were fed sardines [34], Pacific bluefin tuna can be dietary generalists when these high energy fish are not available. Their diet in southern and central California contains variable yet significant proportions of squid and pelagic red crab (Pleuroncodes planipes [55]), with the latter becoming a prominent part of tuna diet during 2014-2016, when these pelagic crabs experienced a range expansion into central Californian waters [56]. While the diet of bluefin tuna is likely to contain fewer squid and crustaceans and relatively more forage fish in the northern parts of their distribution, there remains substantial uncertainty in our understanding of shifts in predator-prey interactions that can only be resolved with a more comprehensive diet data collection throughout their latitudinal range.…”

Impact of the 2014–2016 marine heatwave on US and Canada West Coast fisheries: Surprises and lessons from key case studies

“…Furthermore, the heatwave drove dietary shifts that may have affected availability (Portner et al, 2022). In 2015–2016, bluefin diets abruptly switched to domination by pelagic red crabs ( Pleuroncodes planipes , Munididae), coincident with the anomalous northward advection of this southern crustacean (Cimino et al, 2021). In 2016, bluefin also increased their consumption of anomalously abundant anchovies (Thompson, Ben‐Aderet, et al, 2022).…”

Patrones de distribución de la langostilla (Pleuroncodes planipes) en la costa occidental de la península de Baja California, México

“…El modelo indica que la variable principal que explica la alta densidad de langostillas pelágicas es la temperatura, cuando P. planipes se encuentra en su intervalo preferente de temperatura, la concentración de clorofila-a también muestra su intervalo óptimo a esa misma temperatura, por lo que mejora el desempeño del modelo con una mayor varianza explicada. Cimino et al (2021) analizaron la presencia/ausencia de P. planipes en la costa oeste de Norteamérica (California) sugiriendo que el índice de agua de origen sur, incrementa la varianza explicada en su modelo propuesto.…”

“…Las variaciones ambientales estacionales y los eventos de El Niño y la Niña modifican la distribución y abundancia de la langostilla en la región (De Anda-Montañez et al, 2016). Las condiciones anómalas cálidas persistentes observadas durante 2014-2016 en la región este del Pacífico (Cavole et al, 2016;Cimino et al, 2021) en combinación con el evento de El Niño 2015-2016 favorecieron el transporte hacia el norte de las langostillas cerca de Monterey, California, como ha sido observado en eventos de El Niño previos (Glynn, 1961;Lluch-Belda et al, 2003), e incluso hubo registros en Agate Beach, Oregón en respuesta a las variaciones en la temperatura del mar (Choy et al, 2019;Sandford et al, 2019). Cuando se presenta el evento El Niño y anomalías de temperatura por otros eventos, la langostilla es más propensa al estrés oxidativo (Martínez-Canto et al, 2013).…”