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The putative stock of the Dolphinfish Coryphaena hippurus in the Eastern Pacific Ocean (EPO) ranges from 46°N to 38°S, where seasonal fisheries are developed in waters under the jurisdiction of different coastal countries and in international waters. The Dolphinfish is captured either incidentally or as a target species by artisanal and sport-fishing fleets along its distribution range. In Mexico, this species is reserved for sport-fishing up 50 nautical miles away from the shoreline; however, it is also caught seasonally by artisanal fisheries that operate along the Pacific coast. Off the Baja California Sur (BCS) southern region, the Dolphinfish supports a sport fishery all the year round. Besides the climate variability that affects fish stocks, in recent decades the increase of commercial catches of Dolphinfish in EPO by fisheries of coastal nations in the central and southern part of this range, coupled with the expansion of the recreational fishing fleet in BCS, have raised awareness on the current status of Dolphinfish stocks. Since a comprehensive assessment of Dolphinfish stocks along EPO is not currently available, we provide background on available time-series of data for Dolphinfish in BCS that may be used to develop Stock Status Indicators (SSIs), and provide a preliminary analysis for each SSI. First, the average fork length (FL) of fish landed in BCS, its use is justified because a constant selective fishing of larger fish occurs under recreational fishing, focusing on catches of large, trophy fish. Second, the study of fish condition (Fulton’s K condition factor, KF) based on the analysis of length-weight data assuming that heavier fish of a given length are in better condition. Records of total weight (Wt) and FL for 25,500 fish sampled at Cabo San Lucas, Los Barriles and La Paz were analyzed for the period 1990-2015. The assembled 26-year time-series of SSIs are: 1) annual mean FL by sex; 2) KF by sex including all sizes and months; 3) KF for males in the 75-115 cm size range, caught from April through July; and, 4) KF for females in the 65-105 cm size range for the same months. For revealing the regularities and adaptive traits of fish to the environment, SSIs are related to annual anomalies in sea surface temperature (SST) and Chlorophyll-a concentration (Chl-a) for the coastal area off BCS. We used cumulative sum (CUSUM) plots to detect persistent changes in SSIs and environmental factors, providing a view of the stock history as well as of the variables that may be affecting fish condition. In our study region, SST showed a marked decline from 1998 through 2013, coinciding with the period named ¨global-warming hiatus by several authors, with an upward trend that resumed in 2014, with 2015 temperatures on course for another record-hot year. In general, SSIs time-series showed a low inter-annual variability until 1998, after which it exhibited a positive trend corresponding with the cold period followed by a negative trend associated with an upward trend in SST. Our findings support the hypothesis that trends in fish size and condition for the Dolphinfish are strongly influenced by oceanic conditions.

Palabras clave: Baja California Sur; Dolphinfish; condition factor; CUSUM

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