TheThe JumboJumbo Squid,Squid, DosidicusDosidicus gigasgigas,, aa newnew groundfishgroundfish predatorpredator inin thethe CaliforniaCalifornia Current?Current?
John Field and Ken Baltz Fisheries Ecology Division, NOAA-NMFS-SWFSC Santa Cruz , California
“Although squid fishing is hilarious sport for a few minutes, it becomes too much of a good thing day after day.” (Croker 1937)
(Photo courtesy of Scot Anderson) 5000
Although jumbo squid were 4000
“not uncommon” in the early 3000 part of the century, and catch 2000 abundant in mid-1930s 1000 CPFV North (Croker 1937), they have CPFV South 0 been very uncommon or 1980 1985 1990 1995 2000 2005 absent off of Central CA from 0.05 1940s until late 1990s. Since 0.04 the late 1990s, especially 0.03
2004-2006, they have been 0.02 Freq Occ Freq frequently encountered in 0.01 FO SCB Sea Lion Diet large numbers in fisheries 0 and surveys coastwide 1980 1985 1990 1995 2000 2005 0.05
~70 ton haul of Dosidicus 0.04
0.03
0.02 Freq Occ Freq
0.01 SWC Juvenile Survey 0 1980 1985 1990 1995 2000 2005 CPFV data courtesy Wendy Dunlap and CDF&G, sea lion data courtesy M. Lowry (PRD/SWFSC), SWC Juvenile Survey data from Baltz/Sakuma. Trawl survey data for NWFSC surveys 2002-2006 is pending from NWFSC, but ~ 10-15 positives per year for 2004-2006. Photos courtesy M. Lowry (sea lion, center), S. Webb (squid, bottom), T. Holland (CP vessel, left) ~500 Stomach Samples Collected During 2005-2006
Squid sample locations ranged from San Diego to just south of Cape Mendocino, but most samples were collected off of Cordell Bank and Half Moon Bay on recreational charter vessels targeting squid during the winter months Most animals caught in winter (Jan-Mar) recreational fishery (~300), with ~140 in the Spring NMFS SWFSC midwater trawl survey (May-June, ~ both trawl and line) and ~50 in NMFS NWFSC summer bottom trawl survey. ~60 samples have not been worked up yet (table below shows what has been worked up).
Cordell Bank Half Moon Bay Monterey Bay San Diego NMFS bottom NMFS midwater Samples 81 116 21 25 20 104 # dates/trips 4 5 1 1 ~10 10 seasons Jan-March Jan-March Feb Feb July-Sept May-June Ave ML 67 65 69 60 58 59 0.5 * Size structure based on mantle JanFebMar 0.4 MayJune lengths suggests smaller animals in JulyAugSept spring-summer, largest in winter (pre- 0.3 spawning). Samples from summer 0.2 months are rare with no samples from 0.1 Oct-Dec. Quick disappearance from Frequency Occurrence the central CA rec fishery starting in 0 mid-March indicates post spawning 35 40 45 50 55 60 65 70 75 80 85 die-off. Mantle Length
50.0
* Digestion state and stomach weight 40.0 jig suggests that net feeding occurs in 30.0 traw l many trawl-caught animals (as do bite 20.0 marks on other squid and fish in 10.0 trawl!). However, it is also possible 0.0 Frequency Occurrence that jig-caught squid are hungrier. < 0.0001 0.001 - 0.01 0.01 - 0.1 0.1 - 1 > 1 Stomach Weight (as % BW)
40.0 * Sex information was very spotty and jig some may be unreliable. Maturity 30.0 traw l information was not recorded (we could 20.0 use some help on a key!), but 10.0 anecdotal observations suggest that Frequency Occurrence 0.0 the large, mature females were the 12345 only squid seen in the winter months. Digestion State (1 recent- 5 well digested) Animals were observed feeding on Pacific hake and sablefish from a submersible (Delta sub) near Cordell Bank in Sept. 2005 (video courtesy of Dan Howard, CBNMS, and Rick Starr, CA Sea Grant) Prey items identified with hard parts (otoliths, scales, beaks, vertebrae, shell) using guides, reference collections, etc
Pteropods Mesopelagics
Pacific mackerel
Pacific sardine Bathylagidae sea urchin
Pacific hake & shortbelly rockfish
clubhook squid Aves Pacific sanddab About 50 otoliths & beaks could not be identified (Recognize any of these? Let us know!)
may be pink seaperch
probably Myctophidae F0 % FO N % N Over 1100 prey items Pacific hake (Merluccius productus ) 78 21.3 185 17.5 N. lampfish (Stenobrachius leucopsarus ) 71 19.3 134 12.6 Northern anchovy (Engraulis mordax ) 61 16.6 171 16.1 have been identified, Jumbo squid (Dosidicus gigas ) 52 14.2 53 5.0 Pacific sardine (Sardinops sagax ) 48 13.1 58 5.5 representing ~45 Blue lanternfish (Tarletonbeania crenularis ) 33 9.0 49 4.6 Shortbelly rockfish (S. jordani ) 32 8.7 44 4.2 taxonomic identities Rockfish (Sebastes spp. ) 27 7.4 27 2.5 Unidentified teuthoida 27 7.4 31 2.9 (most indentified to Euphausidae 24 6.5 N/A N/A Cal. headlightfish (Diaphus theta ) 14 3.8 40 3.8 Barracudinas (Paralepididae ) 14 3.8 17 1.6 species or genus level) Pteropoda (Clio spp .) 14 3.8 15 1.4 Blacksmelt (Bathylagus spp. ) 13 3.5 13 1.2 Market squid (Loligo opalescens ) 13 3.5 17 1.6 Gonatid squid (Gonatus spp .) 12 3.3 53 5.0 Unidentified Decapoda 12 3.3 20 1.9 Pacific hake, northern lampfish, northern Pacific sanddab (Citharichthys sordidus ) 6 1.6 13 1.2 Boreal clubhook (Onychoteuthis borealijaponicus ) 51.450.5 anchovy, other Dosidicus, Pacific Slender sole (Eopsetta exilis ) 41.150.5 Plainfin midshipman (Porichthys notatus ) 41.160.6 sardine, blue lanternfish and shortbelly Abraliopsis felis 41.150.5 Aurora rockfish (S. aurora ) 30.830.3 rockfish were among the most frequently Dogtooth lampfish (Ceratoscopelus townsendi ) 30.840.4 osmeridae 3 0.8 3 0.3 occurring prey items. Octopus spp. 30.830.3 Histioteuthis spp. 30.830.3 Pacific herring (Clupea pallasii ) 20.520.2 Only Euphausiid presence/absence was Pacific mackerel (Scomber japonicus ) 20.520.2 Rex sole (Glyptocephauls zachirus ) 20.520.2 noted, as most were too well digested to California lanternfish (Symbolophorus californiensis ) 20.520.2 Jack mackerel (Trachurus symetricus ) 10.310.1 enumerate. Many soft-bodied organisms Bank rockfish (S. rufus ) 10.320.2 Bocaccio rockfish (S. paucispinis ) 10.310.1 (other gelatinous zooplankton?) could be Splitnose rockfish (S. diploproa ) 10.310.1 (other gelatinous zooplankton?) could be English sole (Pleuronectes vetulus ) 10.310.1 Spotted ratfish (Hydrolagus colliei ) 10.310.1 underrepresented in diet studies due to Bigfin eelpout (Lycodes cortezianus ) 10.320.2 Mastigoteuthis dentata 10.310.1 the squids’ high digestion rates. Asteroidea 1 0.3 1 0.1 Echinoidea (likely Strongylocentrotus spp. ) 10.310.1 Teleost unidentified 55 15.0 63 5.9 Size Structure 0.5 Pacific hake (n=136) of Consumed 0.4 0.3 Groundfish 0.2 0.1 Most hake (74%) and flatfish 0 0 5 10 15 20 25 30 35 40 (100%) could be associated 0.5 Small flatfish (n=12) with a otolith-based length, 0.4 while barely half (54%) of 0.3 rockfish could be. Most of 0.2 those that could not, had no 0.1 0 otoliths, as their rock-like 0 5 10 15 20 25 30 35 40 heads were likely not 0.5 consumed, but the vertebrae 0.4 Rockfish (n=32) suggested sizes >30 cm). 0.3 0.2 We are exploring the potential 0.1 for genetic methods (Pearse et 0 0 5 10 15 20 25 30 35 40 al., in press) to identify many Size bins (cm) of the rockfish to species, but no size information would be X-axis is the length of consumed species (cm) possible. Y-axis is the relative frequency of occurrence in stomachs 40 We used length data and groundfish weight/length relationships to infer pelagics 30 more about the relative importance mesopelagics of different prey items. cephalopods 20
% FO % N av wt % Mass % total number % total 10 Pacific hake 21 17 57 24 Non D. gigas squid 19 11 45 12 Northern anchovy 17 16 14 5 0 Mesopelagics 43 25 4 3 0 5 10 15 20 25 30 35 40 Pacific sardine 14 6 44 6 Shortbelly rockfish 9 4 109 11 30 other rockfish 8 3 506 35 small flatfish 4 2 69 3
The inferred sizes of prey suggest 20 that Pacific hake and rockfish (Sebastes) were relatively more
% total mass 10 important than suggested by %FO and %N, with mesopelagics being relatively less important, pelagics 0 and squid other than Dosidicus were 0 5 10 15 20 25 30 35 40 length bin (cm) about the same in importance. Considering the Role of Jumbo Squid in the Ecosystem
Based on adding Dosidicus to a “simplified” food web Ecopath model of the Northern California Current (Field et al. 2006), we see that they fall out as a very high trophic level predator (predation on sablefish inferred from submersible, not from stomach contents). Considering the Role of Jumbo Squid in the Ecosystem
Eastern Tropical Pacific Northern California Current (Olson and Watters 2003) (Field, Francis and Aydin 2006)
Comparing the “Dosidified” California Current model to the ETP model, we see that squid are primarily forage for commercially important species in the ETP, but are predators of many commercially important species in the CCS Considering 5 the Role of 4 ETP 3
Jumbo Squid 2 in the 1 Production/Biomass 0
Ecosystem 2.7 4.4 Sm 3.6 Rays 4.6 Meso 3.8 Auxis 3.4 Crabs 5 Spotted 3.8 Baleen 4.3 Bluefin 3.7 Grazing 5.2 Toothed 5.2
The high production to 4.5 Skipjack 4.6 Albacore 5.1 Lg Bigeye 3.4 Flying fish 4.8 Lg Wahoo 4.8 4.3 Misc. Pisc 4.9 Lg Sharks 4.6 Lg Dorado 4.6 5.3 Lg Marlins 4.8 Lg Sailfish 4.5 Sm Bigeye 3.4 Misc Meso 4.5 Sm Wahoo 5.2 Sm Sharks 4.6 Sm Dorado 5.2 Sm Marlins 4.6 Sm Sailfish 3.6 Sea Turtles 4.6 Lg Yellowfin 3.1 Misc Epi Fish 4.5 Sm Yellowfin 4.4 Cephalopods 4.4 4.7 Pursuit Birds biomass ratio of Lg Swordfish 4.9 Dosidicus is consistent with the distribution of PB 5 values for higher trophic 4 NCC levels in the ETP, but considerably less so in 3 the California Current – 2 What might be the 1 Production/Biomass consequence of range 0 expansions or incursions 3.7 3.6 shelf 4.2 large 3.3 slope 3.6 squid 4 dogfish of fast-metabolism 3.1 dover 2.7 jellies 4.7 sperm 4.1 jumbo 3.2 forage 3.6 Pacific 3.6 baleen 4.4 coastal 4.1 salmon 2.5 benthic 2.8 sardine 3.3 benthic 4.3 lingcod 4.4 toothed 3.3 sml flats 3.1 crustace 4.2 seabirds 3.3 mesopel 3.2 car-zoop 4.0 sablefish 2.7 pandalid 4.1 sablefish 4.4 albacore 4.5 pinniped tropical species into 3.5 mackerel temperate ecosystems dominated by “slower” life histories? Why now?
California Current has a well established history of variable climate on a decadal scale, and previous incursions of squid in the mid-1930s were during the middle of a warm period. There is also increasing evidence of monotonic increases in sea temperature associated with Global Climate Change. In the continental shelf and slope ecosystem, there is also some evidence of shifts in community structure, from long- Secular warming in the CaliforniaCalifornia Current and North lived slow growing species to Pacific. D. Field et al., in press, CalCOFI Reports high turnover species (Levin et al. 2006). However, this would be a pretty extreme example of a fishing-induced change in community structure…… NOAANOAA NMFSNMFS SWFSCSWFSC MidwaterMidwater TrawlTrawl SurveySurvey CoreCore AreaArea andand SamplingSampling StationsStations (1983(1983--2006)2006) 1010 RockfishRockfish SpeciesSpecies SampledSampled byby SWFSCSWFSC TrawlTrawl widow rockfish black rockfish Sebastes entomelas Sebastes melanops 60 yr, 59 cm max 50 yr, 69 cm max schooling schooling, outcrops commercial primarily sport yellowtail rockfish blue rockfish Sebastes flavidus Sebastes mystinus 64 yr, 66 cm max 44 yr, 53 cm max schooling Schooling, nearshore commercial sport
chilipepper bocaccio Sebastes goodei Sebastes paucispinis 35 yr, 59 cm max 45 yr, 91 cm max schooling schooling (various), commecial commercial, depleted squarespot rockfish canary rockfish Sebastes hopkinsi Sebastes pinniger 29 yr, 29 cm max 84 yr, 76 cm max aggregate around outcrops aggregate around outcrops commercial bycatch commercial, depleted shortbelly rockfish stripetail rockfish Sebastes jordani Sebastes saxicola 32 yr, 35 cm max 38 yr, 41 cm max schooling solitary around mud unexploited commercial bycatch Illustrations from Eschmeyer et al. 1983, other information from Love et al. 2002 TrendsTrends inin AbundanceAbundance ofof YOYYOY RockfishRockfish inin thethe CoreCore AreaArea ofof thethe NOAANOAA NMFSNMFS SWFSCSWFSC MidwaterMidwater TrawlTrawl SurveysSurveys (2005(2005 && 20062006 areare LowestLowest YearsYears onon Record)Record)
3.00
2.00
1.00
0.00
-1.00
-2.00 widow yellowtail chilipepper squarespot shortbelly black blue bocaccio canary stripetail -3.00 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Complete Reproductive Failure of Cassin’s Auklets on SE Farallon Island in 2005 & 2006 (slide provided by Bill Sydemen of PRBO) General Conclusions • Dosidicus were rare in the CA Current System prior to the late 1990s, but have been encountered with increasing frequency since then. • Dosidicus will eat just about anything they can capture. When encountered in temperate coastal waters, groundfish (especially semi- pelagic), coastal pelagics, and mesopelagics are important prey. • The impact on the ecosystem is hard to infer given the lack of abundance data, but the potential impact could be substantial, particularly due to the mis-match of tropical v. temperate life histories. • Stomach analysis and preliminary food web modeling indicate that Dosidicus are significant higher trophic level predators in the northern CA Current ecosystem, vs. being a significant forage species in semi- tropical and tropical waters of the Pacific. • In Chile, the hake stock assessment suggested that Dosidicus had a major impact when the frequency of occurrence in trawl surveys increased from 1-2% to 40-50%. Based on California Current resource surveys we’re probably not there yet, but we could be someday… • More research, monitoring, modeling will be key! Acknowledgements This could not have been done without the tremendous help and assistance in collecting samples by a large number of people, particularly recreational and commercial fishing vessel operators! Special thanks to Tom Mattusch and the crew of the Huli Cat, Frank Bertroni, Rick Powers and the crew of the New Sea Angler, John Ymate and crew of the New Seaforth, the Captain and crew of the Sir Randy, the NWFSC FRAM division and the FVs that participated in the 2005 and 2006 bottom trawl surveys, and the Officers and crew of the NOAA Ship David Starr Jordan in 2005 and 2006. We also thank Steve Berkeley, David Field, John Hyde, David Stafford, for their help in collecting samples; Scot Anderson Wendy Dunlap, Mark Lowry, Dan Howard and Rick Starr for sharing their data, photos and videos; and William Gilly, Eric Hochberg, Mark Lowry, Don Pearson, Keith Sakuma, Eric Bjorkstedt, Mike Weiss, and Lou Zeidberg for their help with specimens.