10/5/2015. Theme numero dos: Theme numero uno: Jared Figurski. Life History Traits longevity, fecundity reproductive modes life cycle

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1 Jared Figurski Theme numero uno: How has application of broader ecological understanding contributed to our understanding of the ecology of kelp forest fishes? What have ecological studies of fishes in kelp forests contributed to our broader ecological understanding? Theme numero dos: (species-wide, genetic, reproductive success) Life History Traits longevity, fecundity reproductive modes life cycle distribution Population Attributes structure (size, age, genetic, spatial) dynamics structure (composition, abundance) Community Attributes diversity biogeography dynamics 1

2 Bipartite life cycle of marine organism with pelagic larvae Larvae survive, grow, disperse, develop Bipartite life history of marine species and open populations Pelagic Environment reproduce settlement Benthic Environment Adult Juvenile survive, grow, mature Larval recruitment replenishes local populations!! CLOSED POPULATIONS OPEN POPULATIONS Reef Fish Adult Movement Ranges Production Supply Production Supply 1 Home ranges of 5 west coast rocky habitat fish species Little or no exchange among populations Production Supply Significant exchange among populations Supply Production number of species 8 4 Conclusion: 76% of these species moved less than.5 km Median max. distance (km) Freiwald, J. 1 Can. Jor. Fish. Aquat. Sci.

3 Time in the larval stage (fish) Time in the larval stage (fish) Western North American Coastal Fish Time in Larval Stage midpoint (range) The larval stage of the majority of (reef) fish is 1-3 months. >3 months <1 day 1 month 1-3 months AVERAGE = 94 days Shanks et al. 3 Photo - G. Jones Data from Carr and Syms 6 Fraction of fish species Dispersal of invertebrate larvae: <1-1 km Dispersal Distance (kilometers) passive dispersal invertebrates fishes r =.61, P=.1 mo = 144 hr Time as larvae (hours) Shanks et al. 3 Ecological Applications Genetic difference estimate dispersal distance high Genetic difference low short Isolation by Distance populations nearby one another populations further apart Slope measures average distance of dispersal Geographic distance (kilometers) long 3

4 Genetic difference Slopes estimate dispersal distances high Copper rockfish Rosethorn rockfish CA snails CA corals low 4 6 Geographic distance (kilometers) 8 Number of species Larval dispersal Based on genetic difference Inverts: <1-1 kilometers Fish: - kilometers Palumbi 3 Kinlan and Gaines 3 Temperate reef fish assemblages comprised of BOTH open and closed populations Ecological consequences of larval dispersal: (1) decouples local recruitment (replenishment) from local production () larval recruitment critical to replenishment of local populations (3) recruitment and post-recruitment mortality is important source of population regulation (i.e density dependence) (4) open spatial structure of local and regional populations But remember that openness is a function of: (1) spatial scale: openness decreases as scale of population increases () adult movement: openness decreases as movement increases (3) retention : openness decreases as likelihood that larvae return to adult population increases 4

5 Larval dispersal Settlement Larval production Post-settlement Larval production: - reproductive mode - regional adult abundance - adult fecundity (eggs per female) size/age structure / sex ratio adult condition Reproductive modes of kelp forest fishes: (1) internal vs. external fertilization () internal vs. external eggs (3) external eggs: benthic or broadcast (i) internal fertilization, internal eggs: viviparity e.g., rays, sharks, surfperch, rockfish (ii) internal fertilization, external eggs: ovoviviparity e.g., skates, sharks (swell, horn), sculpins (iii) external fertilization (oviparity), broadcast eggs e.g., kelp bass, wrasses (senorita, sheephead) (iv) external fertilization (oviparity), benthic eggs e.g., greenlings, gobies, damselfishes, kelpfishes Consequences of reproductive modes: (1) openness of a population () behavior and social structure e.g., benthic eggs -- nest guarding, territoriality broadcast eggs -- spawning aggregations (3) Defines resources that influence population distribution and abundance e.g., competition for nest sites Also, some species are hermaphroditic e.g., kelp bass, wrasses (sequential, protogynous) gobies (sequential, protandrous) 5

6 Bigger fish produce far more larvae Approx. 7-fold increase Larval production: - reproductive mode - adult abundance - adult fecundity (eggs per female) Size/age structure / sex ratio adult condition Approx. 11-fold increase Older mothers produce better larvae black rockfish Sebastes melanops GROWTH (WT) GROWTH ( LENGTH) Larvae produced by older females grow faster and survive better Berkeley et al. 4 Ecology; 4 Fisheries LARVAL SURVIVAL Maternal age (yr) Larval production: - reproductive mode - adult abundance - adult fecundity (eggs per female) size/age structure / sex ratio adult condition e.g., Pacific Decadal Oscillation 6

7 Climatic variability effect larval production? Offspring production: climatic variability Ocean climate change Power plant impingement of fish larvae: Holbrook et al Ecological Applications 1) Love et al Fishery Bulletin included commercial species ) Brooks et al. Mar. Freshwater Res. no commercial spp. Ocean climate change Population responses: 4 surfperch species Surfperch production - Bight-wide patterns of juvenile impingement - declines in recruitment for many spp. ( ) - attributed to reduced larval production (but maybe larval survival) - reflecting large-scale decline in productivity Benthic productivity Perch recruitment Larval dispersal (direction, distance, delivery): Larval dispersal (direction, distance, delivery): - larval duration - larval behavior - oceanographic features - interaction among these Larval production: - timing of reproduction - location of reproduction - larval duration - larval behavior - oceanographic features - interaction among these Larval production: - timing of reproduction - location of reproduction 7

8 Physical processes and larval behavior (1) Larval cues: (light, pressure, temperature, structure) e.g., Norris 1963, Ecological Monographs - Opal eye (Girella nigricans) - recruitment related to tide pool temp. - lab experiments: thermal preference - coast-wide patterns of recruitment - hypothesized mechanisms of larval delivery: - internal waves - thermal / structural cues - upwelling ONSHORE TRANSPORT Shanks 1983 Mar. Ecol. Prg. Ser. Large-scale (biogeographic) processes currents e.g., California current - El Nino Large scale patterns of temporal (episodic) variability Hypothesis: Change in current patterns influences spatial patterns of sheephead recruitment Specifically, northward El Nino currents would increase recruitment in northern portion of sheephead range. Cowen 1985 Jour. Mar Research El Nino Normal year (La Nada) Hypothesis: Recruitment of sheephead will be greater in northern portion of range during 1983 El Nino Test: Use annual otolith increments and settlement mark to back-calculate what year individuals settled Use this to construct strength of yearclass recruitment ND Structure - schooling Long larval duration (3-4 months) Olive rockfish Black rockfish Yellowtail rockfish San Nicolas Is. Kelp rockfish Is. San Benito Is. Guadalupe Cabo Thurloe 1 1 ND ND ND Year Benthic - solitary Short larval duration (1- months) Black-&-yellow rockfish Gopher rockfish 8

9 1. Lenarz et al CalCOFI Mid-water complex Long larval duration (3-4 months) Olive, Yellowtail and Black rockfish Kelp, Black-&-yellow, and Gopher rockfish Benthic complex Short larval duration (1- months) Proportion Relative Abundance El Nino El Nino La Nina La Nada (1998) (1999) () Mid-water complex Long larval duration (3-4 months) Olive rockfish Black rockfish Yellowtail rockfish Upwelling Fish per 4 m Olive, Yellowtail and Black rockfish El Niño La Niña Normal (1998) (1999) () Kelp rockfish Black-&-yellow rockfish Benthic complex Short larval duration (1- months) Gopher rockfish Relaxation Fish per 4 m 3 Kelp, Black-&-yellow, and Gopher rockfish El Niño Normal La Niña Sampling Strategy physical processes & biological dynamics (1998) (1999) () 9

10 (3) Smaller-scale, more frequent events (Ammann unpublished) Temperature ( C) Number of fish per sampling unit Number of fish per sampling unit May June July August Year Mid-water complex n = 7 Benthic complex n = 363 May June July August shifts in vertical distribution with ontogeny -- upwelling depth (m) Physical processes and larval distribution e.g., Larson et al. 1994, Lenarz et al. 1995, CalCOFI Rpt.s - vertical distribution of early and late larval rockfishes proportion..4.6 depth structure - schooling spp. benthic - solitary spp. late larvae pelagic juveniles offshore early larvae kelp bed onshore Settlement: - larval cues - habitat structure - priority effects conspecific cues predation competition Settlement (post-settlement): habitat structure (1) Macrocystis (rockfishes in central California) e.g., Carr 1991, JEMBE - manipulated presence of giant kelp - some species recruit to kelp, others to rocky reef () Macrocystis vs. understory (southern California) e.g., Carr 1989, JEMBE - manipulated presence of giant kelp and monitored recruitment - recruitment of some species higher to kelp plots - recruitment of some species higher to understory 1

11 Settlement (post-settlement): habitat structure (3) Macrocystis (kelp bass in southern California) e.g., Carr 1994, Ecology - manipulated kelp density - positive correlation between recruitment and kelp biomass (4) Macrocystis (kelp surfperch in southern California) e.g., Anderson 1994, MEPS - manipulated presence of giant kelp canopy and monitored recruitment (5) Sea urchins (blue-banded goby in southern California) e.g., Hartney and Grorud, Oecologia - manipulated presence of urchins and monitored recruitment Variation in giant kelp (Macrocystis) influences variation in settlement of kelp bass (Paralabrax clathratus) Relationship within reefs Greater density of kelp bass settlers in areas of a reef with giant kelp compared to areas without Density of kelp bass recruits (No. per 6 m 3 ) 3 1 P <.1 Absent Present Macrocystis Spatial and temporal variation among reefs and years kelp bass recruit density (Number per 6 m 3 ) Macrocystis density (Stipes per 3 m ) Density of kelp bass settlers increases with increasing density of giant kelp but it is not linear! Local density of giant kelp DETERMINES local density of kelp bass settlers kelp bass recruit density: (Number / 1 m ) A blade biomass per reef area: (grams / 1 m ) 1, 8 4 A B B Macrocystis density (stipes / 3 m ) B B kelp bass recruit density: (Number per 1 m ) , 1,5 blade biomass (gm per 5 m 3 ) 11

12 Conclusions: i) Local and regional patterns of kelp bass recruitment are influenced by dynamics of giant kelp abundance Settlement: ii) The relationship is not based strictly on plant density, but on biomass (shelter!). Because kelp biomass changes with plant density, recruitment relationship is asymptotic. iii) Giant kelp facilitates recruitment of kelp bass by providing habitat that they encounter as they pass over reefs - larval cues - habitat structure - priority effects conspecific cues predation competition Very little information available! Early post-settlement: predation Early post-settlement: - survival - growth - movement predation competition 1. per-capita mortality black eyed goby kelp perch Initial density Anderson Ecology 1. predators present predators absent Steele 1997 Oecologia kelp rockfish Johnson unpublished

13 (P-) Predator excluded Does local density-dependent predation scale up? Post-settlement mortality is density-dependent + Predators r =.949, P <.1 Predation is the source 15m -- Predators r =.39, P =.67 Local scale density dependence manifested within and across reefs 15m Johnson 6a,b Ecology (P+) Predator exposed Johnson 6a,b Ecology Early post-settlement: competition Conspecific and interspecific resident effects e.g., Steele 1997a, Ecology - black-eyed and blue-banded gobies in So. California - manipulated presence of adults of both - settlement of black-eyed decreased in presence of adult conspecifics - settlement of black-eyed not influenced by presence of adult blue-banned - settlement of blue-banded (+) influenced in presence of adult conspecifics - settlement of blue-banded not influenced in presence of adult black-eyed - survival - growth - movement competition predation Late post-settlement: adult and juvenile interactions 13

14 Late post-settlement: interspecific competition shallow (1) Hixon 198, Schmitt and Holbrook 199, etc. - striped and black surfperch in So. California - two species exhibit depth stratified distributions - manipulated presence of either species - monitored change in depth distribution stripe deep black Late post-settlement: interspecific competition reef: 1 3 Striped (+) Black (+) Striped (+) manipulation Black (+) time: pre- post- Striped (+) Black (+) Striped (+) Black (+) Striped (--) Black (+) Black (+) Black (+) Striped (+) Black (+) Striped (+) Black (--) Striped (+) nobody home Conclusion: striped perch competitively dominant: excludes (interference) black perch from shallow. Late post-settlement: interspecific competition () Larson 198, Ecological Monographs - black-and-yellow and gopher rockfish in So. Calif. - same as above for sibling surfperches shallow black and yellow gopher deep Late post-settlement: intraspecific competition Territory size limits local density and pop. size (1) Garibaldi in So. California -- Clarke map territory sizes and distribution - remove individual - monitored change in territory sizes and density () striped and black surfperch in So. California - Schmitt & Holbrook - same as above (3) black-and-yellow and gopher rockfish in So. Calif. - Larson 198 a, b Marine Biology - same as above 14

15 Effects of habitat on fish assemblages (1) Macrocystis (southern California) e.g., Larson and DeMartini 1984, U.S. Fishery Bull. - compared fish assemblage in areas with and with giant kelp - cobblestone bottom off San Onofre - difference in relative abundance of species () Macrocystis vs. Nereocystis (central California) e.g., Bodkin 1986, U.S. Fishery Bull. - compared fish assemblages on either side of Piedras Blancas (Nereo. north, Macro. south) - difference in relative abundance of species Effects of habitat on fish assemblages (3) Macrocystis (southern California) e.g., Ambrose and Swarbrick 1989, Bull. Mar. Sci. - compared fish assemblage on reefs with and with giant kelp - included artificial reefs - little difference in relative abundance of species (4) Macrocystis (southern California) e.g., Holbrook et al. 199,1994, Austr. J. Ecol., Am. Zool. - same as (3) above, no difference in species richness - planktivores and macro-invert eaters, reduced with kelp Large-scale biogeographic patterns Monterey Bay Sites by Year Sampling Began m m Fish density sizes Pt. Conception Density kelps macro inverts Cover algae inverts 15

16 Approach: within-site sampling design Geographic Variation in Kelp Forest Fish Assemblages Coastline Monterey Bay Sedimentary Sedimentary Granite Granite Basalt Basalt Fish transect distribution 5 m 1 m 15 m m 5 m 1 m m Pt. Pt. Conception Conception Algae / invertebrate transect distribution SIMPROF (P=.1) cold water assemblage Regions North of Point Conception P<.1 R = PC: South Swell PC3: High Relief SIMPROF (P=.1) P=.7 4 P<.15 3 R =.9 3 R =.5 1 PC cold water PC4: Low Relief, Sand PC1: NW Swell High relief rocky reefs protected from high swell exposure P<.1 R =.8 Role of fishes in kelp forest communities (1) Top-down : keystone predators e.g., Cowen 1983, Oecologia - sheephead (Semicossyphus pulcher) in So. Calif. - manipulated local presence of sheephead and observed red sea urchin behavior - urchins more exposed and mobile in absence of sheephead sheephead 16

17 Cascading Effects of Predator Removal Southern California Central California lobster sea otters sheephead Role of fishes in kelp forest communities () Bottom-up : enhanced nutrient availability & productivity e.g., Bray et al. 1991, Science barrens sea urchins kelp forest rockfishes - planktivorous blacksmith (Chromis punctipinnis) hole up in crevices at night - monitored nutrient availability and macroalgal production in crevices with and without blacksmith - greater nutrient availability and macroalgal production in crevices with blacksmith - example of planktivorous fishes directing planktonic production to benthos Role of fishes in kelp forest communities Avoiding the swine flu: don t do this (3) Planktivorous fishes reducing larval supply e.g., Gaines and Roughgarden 1987, Science - reduced recruitment of intertidal barnacles in years with thick Macrocystis forest at Hopkins - high recruitment of planktivorous juvenile rockfishes in years with thick Macrocystis forest - could be hydrodynamic influence of kelp or predation by planktivorous juvenile rockfishes - used barnacle molts to decouple potential causes - barnacle molts not reduced as they passed through forest, concluded reduction due to planktivory 17