Marine Ecology Pelagic Processes Avdp 2024-2025 PDF

MARINE ECOLOGY Course Information Anton Van de Putte 2024 – 2025 RESEARCHER Data manager Policy advisor  E-mail: CONTACT [email protected] SPECIES DISTRIBUTION MODELS  SC AR ANTARCTIC BIODIV ER SIT Y P ORTAL  CCAMLR Commission...

MARINE ECOLOGY Course Information Anton Van de Putte 2024 – 2025 RESEARCHER Data manager Policy advisor  E-mail: CONTACT [email protected] SPECIES DISTRIBUTION MODELS  SC AR ANTARCTIC BIODIV ER SIT Y P ORTAL  CCAMLR Commission for the conservation of Antarctic Marine Living Resources  Marine Ecology Date Time Lecture Lecturer Location 25/09/2024 09:00-12:00 Oceanography, geology, history, and technology MK VUB 02/10/2024 09:00-12:00 Pelagic biological processes AVdP ULB 09/10/2024 09:00-12:00 Benthic biological processes AVdP ULB 15/10/2024 08:00-18:00 Excursion with Simon Stevin (ULB + Tropimundo students) MK Ostend 16/10/2024 08:00-18:00 Excursion with Simon Stevin (VUB students) MK Ostend 23/10/2024 09:00-12:00 Analysis of data collected during the excursion MK VUB 30/10/2024 no lecture 06/11/2024 no lecture COURSE 13/11/2024 09:00-12:00 20/11/2024 Practical Verhaegen AVdP ULB SCHEDULE 27/11/2024 09:00-12:00 04/12/2024 09:00-12:00 Case study: Southern Ocean + global change in the ocean Coral reef ecology AVdP MK ULB VUB 11/12/2024 09:00-12:00 Connectivity of populations MK VUB 18/12/2024 09:00-12:00 Q&A AVdP+MK VUB AVdP: Anton Van der Putte MK: Marc Kochzius Lectures for "Marine Fisheries Ecology and Management" (O&L) and "Fisheries Management" (MSc Biology VUB) VUB D.0.02 ULB S.UC2.236  COURSE INFORMATION https://uv.ulb.ac.be/ https://biomar.ulb.ac.be https://canvas.vub.be/ (might be delayed)  TEACHING SUPPORTS Slides of the course Books At the « Bibliothèque des Sciences et Techniques » Both ULB and VUB students have access (for the latter, contact the desk in the library) Advanced course: not covered by a single book, even not by multiple ones; several parts based on original scientific literature « Framework »:Valiela I. 2015. Marine Ecological Processes. Springer (on line version available).  « Framework »:Valiela I. 2015. Marine Ecological Processes. Springer. Thurman HV. 1990. Essentials of oceanography 3rd ed. Columbus, Ohio : Merrill Pub. Co Segar DA 2007. An introduction to ocean sciences 2nd edition. Minneapolis/St. Paul, MN: West Pub. Levinton JS 1995. Marine biology : function, biodiversity, ecology. New York : Oxford University Press 420 p. Sheppard Ch 2000. Seas at the millennium : an BOOKS environmental evaluation New York : Pergamon Steele, John H.2001 Encyclopedia of ocean sciences vol 1- 6 Castro & Huber 2019 Marine Biology McGraw Hill, New York  Taught in English but Most of us are not native speakers Not an English language course Do not hesitate to ask questions (rather small audience) ENGLISH Exam In English (prefered) But you have the right to have it in French (ULB students) or in Dutch (VUB students) (NB: Tropimundo in English, mandatory) THE COURSE WITHIN YOUR MASTER Marine Biology does not stop at the end of the course! Depending on your cursus further excursions during your Master on temperate or tropical shores: you’ll need what you learned in this course! (ULB MA-BIOR A-D: BIOL-F-416 Stage de Biologie marine)  Method(s) of evaluation Oral examination starting with the critical presentation of a scientific article in relation with the course (submitted for approval to the titular) Written reports for the practicals EVALUATI ON Mark calculation method (including weighting of intermediary marks) If the marks for the oral exam and practicals are both higher or equal to 8/20, then the final mark will be calculated as 70% for the oral exam and 30% for the practicals.If the mark of either the oral exam or the practicals is lower than 8/20, then the final mark will be the lower of these.  Oral, 30 minutes long 13-14 January 20-21 January EXAM Exact time and data will be planned together with you Be present 30 minutes in advance  Short introduction to the question 10 minutes PowerPoint presentation of a Short explanation of the experiments scientific article in direct designed to answer the question (do relationship with the course not enter into the details of the “Materials and Methods” section) Results (to be supported by graphs/tables) Discussion and conclusions are the results convincing? 10 minutes discussion of the subject of the paper Your own critical assessment of the Is the statistical support sufficient? EXAM STRUCTURE presented article do results support the conclusions? 10 minutes general questions for the course  For the discussion, the knowledge of the course is necessary! This discussion may possibly bring you to other subjects (transverse comparisons). EXAM So, if you choose an article on the impact of STRATEGY global change on coral reefs, expect questions dealing with coral reefs but also on chemical oceanography or on top-down control in benthic ecosystems (for instance). Articles from Nature and Science are hard!  EXAM ARTICLE a recent (2016-2024) scientific research article not a review, not a descriptive faunistic list, not a data paper, not a popular science paper avoid inventories or natural history of a species or taxon in relationship with the course ecological processes; effects of global change; connectivity in the marine environment in case of a modelling article, be sure to master the modelling aspects (be able to explain how an independent variable is acting on the dependent variables)  EXAM ARTICLE EXAMPLES Are fisheries impacting breeding seabirds of the North Sea? Are coral reef sea urchins controlled by bottom-up or top-down factors? Do the introduced starfish Asterias amurensis have an impact in Southern Australia? Do food or wave impact control biodiversity on sandy beaches? QUESTIONS  MARINE ECOLOGY Marine relating to or found in the sea Ecology the study of organisms and how (Ocean, Sea, Estuary) they interact with the environment around them FUNDAMENTALS OF BIOLOGY AND ECOLOGY  The study of relationships between organisms and their environments, focusing on interactions that include physical, chemical, and biological processes (Schroeder, 1996) ECOLOGY It is concerned with the totality of these interactions, which can be observed at various levels, such as individual organisms, populations, communities, and ecosystems(Dyksterhuis et al., 1959) (Kormondy, 1969). ECOSYSTEM  PRIMARY PRODUCTION photosynthesis 6CO2 + 6H2O → C6H12O6 (carbohydrate) + 6O2 respiration conversion of inorganic compounds into organic compounds. Mostly photosynthesis Some chemosynthesis  NEW SOURCE OF OXYGEN Clarion–Clipperton Zone polymetallic nodules A polymetallic nodule found on the sea floor, which Sweetman, A. K. et al. Nature Geosci. researchers think could be involved in the oxygen https://doi.org/10.1038/s41561-024-01480-8 (2024). production.Credit: Camille Bridgewater HOW POPULATIONS GROW  R AND K STRATEGIST 25 r-organisms K-organisms 20 short-lived long-lived small large 15 weak strong or well-protected Population Size waste a lot of energy energy efficient 10 less intelligent more intelligent Have many offspring Have few offspring 5 reproduce at an early age reproduce at a late age fast maturation slow maturation 0 little care for offspring much care for offspring 0 5 10 15 20 25 Time small size at birth large size at birth R strategist K strategist Carrying capacity R AND K STRATEGIST SURVIVOR SHIP CURVE  ECOLOGICAL NICHE abiotic and biotic To grow, reproduce, and survive FUNDAMENTAL VS REALIZED NICHE  Finite quantity of resources PRINCIPLE OF ALLOCATION Zero sum game leads to trade-offs QUESTIONS  THE PELAGIC ENVIRONMENT πέλαγος (pélagos) 'open sea’ NERITIC PROVINCE  OCEAN CIRCULATION (RECAP) Surface Thermohaline circulation circulation Surface currents SURFACE Coriolis effect CIRCULATION Up- and downwelling  CORIOLIS EFFECT Northern hemisphere: deflection to the right Southern hemisphere: deflection to the left GLOBAL WIND PATTERS SEA SURFACE TEMPERATURES AND GYRES EKMAN TRANSPORT UP- AND DOWNWELLING  Chile Peru Oregon California COASTAL UP- AND DOWNWELLING  UP- AND DOWNWELLING (Castro & Huber 2010)  SOUTHERN OCEAN UPW ELLING Driven by westerlies  UPWELLING AND DOWNWELLING Upwelling Coastal Equatorial Antarctic Downwelling Centre of oceanic gyres Coastal downwellings (Castro & Huber 2010) THERMOHALINE CIRCULATION Ocean is stratified Light water warm “light” Dense water Cold Dense  The ocean has three main layers: the surface or mixed layer, the intermediate layer, and the deep layer.  LATITUDAL VARIATION Surface temperature varies with latitude, highest surface temperature in the tropics. Deep-water temperature and salinity much more uniform  SEASONAL VARIATIONS Summer Autumn Winter  The globe viewed on a Spilhaus projection; in contrast to conventional projections, this portrays the ocean fringed by land. The global thermohaline circulation is shown in cartoon form, with upper-layer flow in red and lower-layer flow in blue. NABW ABW © Spilhausen map Mike Meredith NABW ABW Segar 2007 QUESTIONS 1. DIVISIONS OF THE MARINE ENVIRONMENT πέλαγος (pélagos) 'open sea’ OCEANIC PROVINCE 1. DIVISIONS OF THE MARINE ENVIRONMENT 1.1. ZONES OF THE PELAGIC DOMAIN Epipelagic zone (0-200m): Euphotic and Mesophotic Mixing zone Superficial water masses Mesopelagic zone (200 - 1000m): Disphotic Intermediate water masses Bathypelagic zone (1000 - 4000m): Aphotic Deep water masses Abyssopelagic zone (below 4000m): Aphotic Bottom water masses Originating from high latitude sinking water Hadalpelagic zone(below 6000m): Aphotic  SIMPLE ECOSYSTEM Primary Producers Consumers & Food Chain Detritus & DOM Detritus and DOM  GASSES IN THE OCEANS Gasses Air Total Ocean Surface Ocean oxygen (O2) N2 78% 11% 48% carbon dioxide (CO2) O2 21% 6% 36% nitrogen (N2) CO2 0.04% 83% 15% Solubility Total 99.04% 100% 99% Pressure Temperature Salinity OXYGEN  OXYGEN Surface exchange from atmosphere Produced by primary productivity Oxygen minimum layer No exchange No primary productivity Deep water Cold high pressure Ocean circulation  NITROGEN AND NUTRIENTS Surface used by primary producers Increase with depth No longer consumed No primary productivity Deep water Regenerated through decomposition 1.2. VERTICAL DISTRIBUTION OF O 2 AND NUTRIENTS Epipelagic zone (0-200m): Low nutrients High pO2 Mesopelagic zone (200 - 1000m): ↓ pO2 (min. ca 700m) ↑ nutrients Bathypelagic zone (1000 - 4000m): ↑ pO2 ( >bottom waters) ± constant nutrients Abyssopelagic zone (below 4000m): ↑ pO2 ( >bottom waters) ± constant nutrients QUESTIONS  P E L AG I C ECOSYSTEMS  PLANKTON Seston Plankton: Unable to move against currents (dependent on the water mass) Tripton: Particulate organic matter (POM) / marine snow "Marine snow" Photo: Henk-Jan Hoving/GEOMAR  NEKTON Nekton: Able to swim against currents (independent on water masses) © Bruno de Giusti. An underwater picture taken in Moofushi Kandu, Maldives, showing predator bluefin trevally sizing up schooling anchovies  PLANKTON Plankton Zooplankton Phytoplankton Mixoplankton (autotroph) (heterotroph) (Mixotroph) Natureasia.com  PLANKTON Holoplanktonic: spend their entire life in the plankton, drifting wherever the currents take them. copepods, certain jellyfish species, some diatoms and amphipods.  PLANKTON Meroplanktonic spend only a portion of their life cycle in the plankton. larval crabs and lobsters live in the plankton for the first portion of their life until they are large enough to settle on the seafloor. copepods, certain jellyfish species, some diatoms and amphipods. Larval fish  PLANKTON Meroplankton seastar barnacles  2.1. DEFINITIONS Aquaticlivefood.com.au Ultraplankton < 2µm Classification according to size Nanoplankton 2 – 20 µm Microplankton 20 – 200 µm Net Plankton Mesoplankton 0.2 – 20 mm macroplankton 2-20 cm Megaplankton 20-200 cm Daylymail.co.uk  PYTHOPLANKTON Diatoms dinoflagellates Silicate dioxide box (frustulae) Two flagella Generally larger Generally smaller  HARMFUL ALGAE BLOOMS Blooms can harm people, animals, and the environment when they Produce toxins (poisons) Become too dense Use up the oxygen in the water Release harmful gases A harmful algal bloom offshore of San Diego County, California. (NOAA, With permisson from Kai Schumann)  HARMFUL ALGAE BLOOMS Cyanobacteria (sometimes called blue-green algae) (freshwater) Dinoflagellates (sometimes called microalgae or red tide) Diatoms (sometimes called microalgae or red tide) QUESTIONS  EPIPELAGIC Primary Production  2.2. PRIMARY PRODUCTION photosynthesis 6CO2 + 6H2O → C6H12O6 (carbohydrate) + 6O2 respiration conversion of inorganic compounds into organic compounds. Mostly photosynthesis Some chemosynthesis  2.2. PRIMARY PRODUCTION — Gross primary productivity: total amount of organic material synthesized during photosynthesis or chemosynthesis. — Net primary productivity: difference between the gross productivity and the amount of organic material used during respiration. — Respiration: energy required for metabolic activity — Net productivity = Gross productivity - Respiration  LIGHT AND DARK BOTTLE TECHNIQUE depth 1 depth 2 photosynthesis depth 3 respiration depth 4 respiration Collection Incubation  14C METHOD — A known amount of radioactive carbon in the form of bicarbonate is added to a water sample. — The uptake of carbon by the primary producers is determined by measuring their radioactivity.  STANDING CROP OF PHYTOPLANKTON — Phytoplankton are free-floating microscopic plants which are the primary producers of the oceanic system. — In this method, either the number of plankton or the total weight of plankton per unit volume or unit area is measured. — Standing crop is not equal to productivity  PRIMARY What are limiting factors? PRODUCTION  Light PRIMARY PRODUCTION Nutrients LIGHT IN THE OCEAN  LIGHT Sea water absorb the photosynthetic active radiation (PAR) Iz: PAR at depth Iz= I0 e-kz Where k: extinction coefficient z: depth I0: surface PAR  LIGHT Light limiting Saturation Photoinhibition UV Light induced respiration Leakage of organic molecules Differs according to taxa PRODUCTION RESPIRATION  LIGHT Sea water absorb the photosynthetic active radiation (PAR) But respiration ≠ function of depth Ø Compensation depth: R = F for a particular species LIGHT  LIGHT + Pri Prod Mixing depth < Ø Critical depth: SR = S F crit depth for the whole P1 + Pri Prod community (net P1 of the community = 0) Use stocked energy Mixing depth > crit depth Pri Prod BREAK  NUTRIENTS What is a nutrient ? Only for P1, not for consumers ! Major nutrients: C, N, P, O, Si, Mg, K, Ca N: proteins Inorganic forms in sea water: Abundant in sea water NH4+ : no reduction necessary → most favorable NO3-, NO2- : have to be reduced (nitrate reductase) Most marine inorganic N as NO3- (1µM to > 25 µM) (Nitrite) P: energy storage (ATP), enzyme phosphorylation Inorganic forms in sea water: Dissolved Inorganic Phosphate (PO42-) (most favorable) Dissolved Organic Phosphate Si: diatom frustule Trace nutrients: Fe, (Cu,V, Cd) Organic nutrients: vitamins  NUTRIENTS 4 nutrients are possibly limiting Nitrogen (N) Phosphorus (P) Silicon (Si) Iron (Fe)  NUTRIENTS Uptake Described by Michaelis-Menten equation: V= Vmax. C Ks + C Vmax= Uptake velocity at saturation C= nutrient concentration in SW Ks= nutrient concentration in SW at which V= Vmax/2 (constant)  NUTRIENTS Uptake: low and high Ks Species with a low Ks favoured in low nutrients Ks1 < Ks2 concentrations but lower capacity → no or limited Vmax1 < Vmax2 blooms Species with a high Ks favoured in high nutrients concentrations and able to incorporate high amounts of nutrients → blooms Uptake rate Nutrient concentration  NUTRIENTS Ks depends on size  NUTRIENTS Ks differ according to habitat Valiela 2009  NUTRIENTS Ks Usually lower in nano- (flagellates) than in microphytoplankton (diatoms) Biology.kenyon.com Usually higher in coastal communities rich in nutrients (selection for high Ks species) www.Labroots.com NUTRIENTS N AND P Skeletonema costatum Valiela 2009 NUTRIENTS N AND P Valiela 2009  NUTRIENTS Sources of N (and P) 1. Fixation of Atmosperic N2 2. Land run-off (rivers): principally NO3- 3. Coastal bottom waters (upwelling!): principally NO3- 4. Excretion/elimination by water column consumers: principally NH4+ NO3- based P1: « new production » NH4+ based P1: « regenerated Simplified nitrogen cycle in the ocean. Coloured dots represent the marine production » bacteria responsible for nitrogen cycling © Introduction to Oceanography by Paul Webb  NUTRIENTS low at the surface rapidly consumed do not have the chance to accumulate levels increase at depth no longer consumed regenerated through decomposition Representative nutrient (nitrate) profile for the open ocean Nitrate profile from an open-ocean location in the South Atlantic (52o S, 35o13’58.8″ W), north of South Georgia Island (image by PW, data from 2014, World Ocean Database). Representative nutrient (nitrate) profile for the open ocean © Introduction to Oceanography by Paul Webb © Spilhausen map Mike Meredith  Figure 1. Nitrate concentrations in (a) surface waters of the ocean and (b) at 1000 m depth The marine nitrogen cycle: recent discoveries, uncertainties and the potential relevance of climate change, Volume: 368, Issue: 1621, DOI: (10.1098/rstb.2013.0121)  Atmosphere NITROGEN CYCLE Nitrogen gas Nitrates Dissolved Herbivory Primary Producers nitrogen gas A b so r p t ion Absorption Food Chain Fixed Consumers Excretio Nitrogen n Excretion Ammonia Nitrites Detritus Feeding Nitrate Decomposition Nitrates Death Sediments and deep sea Detritus and DOM Death Excretion  NUTRIENTS C:N:P N and P In most marine environments, N is the main limiting nutrient P is limiting in some eutrophicated environments (see later) NUTRIENTS C:N:P  NUTRIENTS C:N:P C:N:P In many phytoplanktonic primary producers, the C:N:P ratio is typically 106 : 16 : 1 = Redfield ratio If Sea Water nutrient concentrations depart from this ratio, a limitation is very probable  NUTRIENTS C:N:P Green algae cyanobacteria PHOSPHATE Phosphate profile from an open-ocean location in the South Atlantic (52o S, 35o13’58.8″ W), north of South Georgia Island (image by PW, data from 2014, World Ocean Database).  Atmosphere PHOSPHORUS CYCLE Phosphate Rivers (Phosphate) Herbivory Primary Producers Ab so r Food Chain p tio n Consumers Res pir at i o Dissolved ti on n Excre Phosphate Death Excretion Decomposition Death Detritus Excretion Feeding Detritus and DOM Sediments  NUTRIENTS: SI Si limitation may terminate diatom blooms Few clearly documented cases silicate profile from an open-ocean location in the South Atlantic (52o S, 35o13’58.8″ W), north of South Georgia Island (image by PW, www.Labroots.com data from 2014, World Ocean Database).  NUTRIENTS FE Component of ferredoxin involved in electron transfer from photosystem I to NADP+ From terrestrial origin (rivers, airborne) ←→ high concentrations (1 – 3 nM) in coastal zones, low to very low concentrations (herring -> mackerel - >tuna Based on net plankton  PLANKTON= NEW UNDERSTANDING Finer Filters fluorescent dyes Genomics Metagenomics  PLANKTON= NEW UNDERSTANDING Femtoplankton virusses Picoplankton Archaea (cyano)Bacteria (>=50% Primary production) Nanoplankton  PROTOZOANS Small enough to consume pico- and nanoplankton Flagellates Cilliates Foraminiferans radiolarians MICROBIAL LOOP Bacteria: bottom-up control by nutrients (inorganic and organic)  MICROBIAL LOOP Bacteria: top-down control by nanoflagellates What Is bad about these figures? In the field In the lab. MICROBIAL LOOP Nanoflagellates (auto- and heterotrophs): top- down control by ciliates EPIPELAGIC FOODWEBS. MICROBIAL LOOP Where Energy flow: Pn: production of trophic level n P1: primary production of the community Pn = P1. En Energy absorbed by level n E: ecological efficiency= Energy ingested by level n E humans, birds, and amphibians Up to one quadrillion individuals or 10^15 fish!  CARBON PUMP Limnology & Oceanography, Volume: 66, Issue: 5, Pages: 1639-1664, First published: 17 February 2021, DOI: (10.1002/lno.11709) FOOD CHAINS AND FOODWEBS  Sankey diagram depicting predator-prey interactions between mid-trophic level groups of interest and marine mammal and bird functional groups within the Prydz Bay © McCormack et al.2020 c  network diagram for the 50 trophic groups and their associated interactions Nodes are colored according to broad taxonomic groups (e.g., yellow for benthic organisms, red for zooplankton) with numbers corresponding to the name of the group listed in the key. Silhouettes are representative of the types of organisms associated with each node. Edges (i.e., connections) are colored according to prey species/group and are directed toward the relevant predator node. This overall representation shows the complexity of trophic connections present in the database, which are more clearly resolved in regional food web configurations © McCormack et al.2020 b  Food chains don’t exist in real Many species don’t fit in convenient ecosystems categories Almost all organisms are eaten by more Omnivores than one predator (and vice versa) Detrivores Food webs reflect the multiple and Parasites shifting trophic interactions. Cannibalism  09:00- 09/10/2024 12:00 Benthic biological processes AVdP ULB 08:00- Excursion with Simon Stevin (ULB + 15/10/2024 18:00 Tropimundo students) MK Ostend 08:00- Excursion with Simon Stevin (VUB 16/10/2024 18:00 students) MK Ostend NEXT CLASSES  PRACTICAL: ONLINE RESOURCES FOR MARINE BIODIVERSITY DATA Bring laptop No special software needed Work with same groups as other practical Class 30 minutes intro to online resources Work together to find information on a marine taxon Small ‘literature’ report MARTINS LAW For sinking particles transfer efficiency is a function of sinking speed and remineralization rate: Fz=Fz0e−(rz)/v fast remineralization and slow sinking retains matter near the surface ocean, slow remineralization and fast sinking allow organic Fz=Fz0(z/z0)−b matter to be transported much deeper. Assuming that remineralization rate (r) and sinking speed (v) are constant with depth, flux (F z ) at a depth (z) can be calculated from a reference flux (F z0) as: Observations of particle flux profiles suggest that particle flux is better described by an empirical power- law function known as the “Martin curve” (Martin et al. 1987): This power-law function implies that particle sinking speeds increase, and/or remineralization rates decrease, with depth. For carbon, “Martin’s coefficient” b varies regionally with a global average of 0.86, while other elements have different values due to varying remineralization and transfer rates Y = 194.9 (X / MLD)−0.71 (R 2 = 0.42, p = 0.060, n = 9) Anna Belcher, Morten Iversen, Sarah Giering, Virginie Riou, Stephanie A. Henson, Leo Berline, Loic Guilloux and Richard Sanders - doi:10.5194/bg- 13-4927-2016  Atmosphere C ARBON CYCLE CO2 Herbivory Primary Producers Ph o tos yn t Food Chain hes is Consumers Res pir at i o Dissolved ir at i o n n R e sp CO2 Death Excretion Decomposition Death Detritus Excretion Feeding Detritus and DOM CaCO3 dissolves Sediments CaCO3  Atmosphere NITROGEN CYCLE Nitrogen gas Nitrates Dissolved Herbivory Primary Producers nitrogen gas A b so r p t ion Absorption Food Chain Fixed Consumers Excretio Nitrogen n Excretion Ammonia Nitrites Detritus Feeding Nitrate Decomposition Death Detritus and DOM Death Excretion  Atmosphere PHOSPHORUS CYCLE Phosphate Rivers (Phosphate) Herbivory Primary Producers Ab so r Food Chain p tio n Consumers Res pir at i o Dissolved ti on n Excre Phosphate Death Excretion Decomposition Death Detritus Excretion Feeding Detritus and DOM Sediments  NITROGEN AND NUTRIENTS Nitrogen fixation Cyanobacteria Ammonium NH4+ Nitrification bacteria Nitrite NO2- Nitrate NO3- Decomposition Denitrification bacteria N2  NITROGEN AND NUTRIENTS Surface used by primary producers Increase with depth No longer consumed No primary productivity Deep water Regenerated through decomposition  Atmosphere C ARBON CYCLE CO2 Herbivory Primary Producers Ph o tos yn t Food Chain hes is Consumers Res pir at i o Dissolved ir at i o n n R e sp CO2 Death Excretion Decomposition Death Detritus Excretion Feeding Detritus and DOM CaCO3 dissolves Sediments CaCO3