DOCSLIB.ORG

Herbivores Pelagic Food

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Herbivores Pelagic Food Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Pelagic Food Web: Review Pelagic Food Web: Herbivores • Primary Producers • Primary Consumers – Diatoms – Microzooplankton • www.ucl.ac.uk/GeolSci/micropal/foram.htm www.radiolaria.org – Crustaceans – Dinoflagellates • Copepods • Herbivorous krill – Pteropods – Microflagellates – Larvae – Chordates 1 2 Barnacle Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Pelagic Food Web: Carnivores Pelagic Food Web: Carnivores • Secondary consumers preying on zooplankton • Tertiary consumers preying on herbivorous & – Gelatinous zooplankton carnivorous zooplankton • Medusae – Fish (“baitfish,” “forage fish”) • Ctenophores • Herring • Siphonophores • Anchovy • Chaetognaths • Sardine – Crustaceans • Smelt • Carnivorous krill • Sand Lance – Amphipods & juveniles shrimp • Juvenile salmon • Predatory copepods – Invertebrates – Fish larvae & juveniles • Squid 3 4 http://jaffeweb.ucsd.edu/pages/celeste/copepods.html Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Pelagic Food Web: Carnivores Pelagic Food Web: Carnivores • Tertiary consumers preying on herbivorous & • Predators on krill zooplankton & small fish carnivorous zooplankton • Mammals – Planktivorous Fish – Baleen whales • Pink salmon – Filter feeders Sockeye salmon • • Blue Pollock • • Minke • Hake • Humpback Cod • • Right • Dogfish 6 • Fin • Lanternfish • Sei 5 Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Pelagic Food Web: Carnivores Pelagic Food Web: Carnivores • Predators on krill zooplankton & small fish • Predators on small fish • Diving birds – Coho salmon – Puffins • Chum salmon – Murres • Chinook salmon • Mackerel – Auklets • Top predators – Guillemots – Tuna – Grebes – Sharks – Pelicans – Billfish – Albatrosses 7 8 Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Pelagic Food Web: Carnivores Generic Food Web • 5. Large fish, • Top predators: Mammals birds, – Seals mammals • 4. Small fish – Sea lions (herring, smelt) – Toothed whales • 3. Carnivorous • Orca zooplankton (medusae, • Porpoise (dolphin) amphipods, some • Sperm copepods, fish larvae) • 2. Herbivorous zooplankton (copepods, larvae) • 1. Phytoplankton 9 Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Food Webs in Different Zones Productivity in Ocean Zones • Differences dictated by two properties: – Amount of primary productivity – Type of phytoplankton • Upwelling zones – High productivity • Upwelling zones have – Large, fast-growing diatoms highest productivity • Neritic zones & temperate oceanic zone – Nutrient supply – Moderate productivity • Coasts (& temperate – Large diatoms mixed with dinoflagellates oceans) next • Low-latitude oceanic zone • Low-latitude open ocean NOTE: Biomass used here as 11 – Low productivity of small microflagellates 12 lowest an indicator of productivity Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Productivity in Ocean Zones Productivity in Ocean Zones • Upwelling zones still • But upwelling zones provide <1% of total provide 58% of total ocean production fish production – Small area • Coasts (& temperate • Coasts (& temperate oceans) 37%, open oceans) next, open ocean ocean 5% NOTE: Biomass used here as NOTE: Biomass used here as 13 highest because of area an indicator of productivity 14 – Why? an indicator of productivity Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Productivity in Ocean Zones Food Webs in Upwelling Zones • Peru a special case – Primary producers large, fast-growing diatoms – Primary consumer Peruvian anchovy • An unusual herbivorous fish Upwelling zones • – Result: fishery harvest @ trophic level 2 have: – Dense, compact area of production – Shorter food chains • Efficiency = 20% – Greater trophic • Less energy expended to search for food efficiency • Harvestable • The main difference fish production NOTE: Biomass used here as = 20% of primary 15 is in the food chains an indicator of productivity 16 production • Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Food Webs in Upwelling Zones Food Webs in Neritic Zones • More typical upwelling area: California • Example area: Bering Sea – Primary producers – Primary producers • Large, fast-growing diatoms • Nutrients not as abundant – Primary consumers (level 2) • Diatoms & dinoflagellates • Copepods & krill – Primary consumers (level 2) – Secondary consumers (level 3) • Copepods & krill • Anchovies & sardines – Secondary consumers (level 3) – Tertiary consumers (level 4) • Carnivorous ZP & juvenile fish • Mackerel, salmon – Tertiary consumers (level 4) – Fish harvest from levels 3 & 4 • Pollock, salmon • Estimated global production – Fish harvest from levels (3 &) 4 4 5 6 17 46 * 10 - 10 , not 10 18 • Food less concentrated, 15% efficiency Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Food Webs in Oceanic Zones Food Webs in Oceanic Zones • Example area: North Pacific • Example area: North Pacific – Primary producers – Tertiary consumers (level 4) • Nutrients scarce: microflagellates • Small oceanic fish • Nitrogen fixing cyanobacteria – Lanternfish (myctophid) Productivity sustained by nutrient » Most abundant fishes in the world • because of open ocean area? regeneration near surface – Flying fish – Primary consumers (level 2) – Dorado (mahi mahi) • Microzooplankton – Ocean sunfish (mola mola) – Secondary consumers (level 3) – Mostly not significant • Carnivorous copepods & krill commercially harvested • Same size as herbivorous species species that live in more productive waters • Too expensive to catch 19 20 for market value Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Food Webs in Oceanic Zones Food Webs in Oceanic Zones • Example area: North Pacific • Example area: North Pacific – Top predators (level 5) – Five-level food chain • Large oceanic fish – Lower trophic efficiency (10%) – Tuna • Energy expended to find widely – Swordfish, marlin dispersed food by energetic migrators – Sharks – Result: – Significant commercially harvested species • Classic food-chain model of 10% loss at each trophic level • Valuable enough to justify expense of • Harvestable fish production is 10-5 fishing far from shore times primary production • They save fishermen the work of scouring the sea to catch smaller fish – Combination of: • Highly mobile, energetic migrators • Low primary productivity, small 21 22 phytoplankton, widely dispersed food Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Oceanography 101, Richard Strickland Lecture 26 © 2006 University of Washington Food Chain Productivity Food Chain Productivity • Trophic pyramid is a simple (simplistic) model • Upwelling – Illustrates underlying principles of: – 1000 * (0.2) = 200 • Number of – 1000 * (0.2)2 = 40 trophic levels • Neritic • Differences – 1000 * (0.15)3 = 3.4 in trophic • Oceanic efficiency – 1000 * – This diagram (0.1)4 does not = 0.1 include diff- erences in 23 primary productivity 24.
Load more

Recommended publications
  • Bay Shore Power Plant Cooling Water Intake Structure Information and I&E Sampling Data
    BAY SHORE POWER PLANT COOLING WATER INTAKE STRUCTURE INFORMATION AND I&E SAMPLING DATA Kinectrics Report: 112026-005-RA-0002-R00 January, 2008 Darlene Ager, Ph.D., David Marttila, Eng, Paul Patrick, Ph.D. Environmental and Aquatic Management Services PRIVATE INFORMATION Contents of this report shall not be disclosed without the consent of the Customer. Kinectrics has prepared this report in accordance with and subject to the contract Terms and Conditions between Kinectrics and FirstEnergy, dated October 7, 2004 © Kinectrics North America Inc., 2008 Kinectrics North America Inc., 800 Kipling Avenue Toronto, Ontario, Canada M8Z 6C4 BAY SHORE POWER PLANT COOLING WATER INTAKE STRUCTURE Kinectrics Report: 112026-005-RA-0002-R00 January, 2008 Darlene Ager, Ph.D., David Marttila, Eng. Paul Patrick, Ph.D. Environmental and Aquatic Management Services EXECUTIVE SUMMARY Section 316(b) of the Clean Water Act (CWA) requires that cooling water intake structures reflect the best technology available for minimizing adverse environmental impact to aquatic organisms that are impinged (being pinned against screens or outer part of a cooling water intake structure) or entrained (being drawn into and through cooling water systems). Phase II of the 316(b) rule for existing electric generating plants was designed to reduce impingement mortality by 80-95% and, if applicable, entrainment by 60-90%. In January 2007, the Second U.S. Circuit Court of Appeals remanded several provisions of the Phase II rule on various grounds. The provisions remanded included: • EPA’s determination of the Best Technology Available under Section 316(b); • The rule’s performance standard ranges; • The cost-cost and cost-benefit compliance alternatives; • The Technology Installation and Operation Plan provision; • The restoration provisions; and • The “independent supplier” provision.
    [Show full text]
  • Backyard Food
    Suggested Grades: 2nd - 5th BACKYARD FOOD WEB Wildlife Champions at Home Science Experiment 2-LS4-1: Make observations of plants and animals to compare the diversity of life in different habitats. What is a food web? All living things on earth are either producers, consumers or decomposers. Producers are organisms that create their own food through the process of photosynthesis. Photosynthesis is when a living thing uses sunlight, water and nutrients from the soil to create its food. Most plants are producers. Consumers get their energy by eating other living things. Consumers can be either herbivores (eat only plants – like deer), carnivores (eat only meat – like wolves) or omnivores (eat both plants and meat - like humans!) Decomposers are organisms that get their energy by eating dead plants or animals. After a living thing dies, decomposers will break down the body and turn it into nutritious soil for plants to use. Mushrooms, worms and bacteria are all examples of decomposers. A food web is a picture that shows how energy (food) passes through an ecosystem. The easiest way to build a food web is by starting with the producers. Every ecosystem has plants that make their own food through photosynthesis. These plants are eaten by herbivorous consumers. These herbivores are then hunted by carnivorous consumers. Eventually, these carnivores die of illness or old age and become food for decomposers. As decomposers break down the carnivore’s body, they create delicious nutrients in the soil which plants will use to live and grow! When drawing a food web, it is important to show the flow of energy (food) using arrows.
    [Show full text]
  • Forage Fishes of the Southeastern Bering Sea Conference Proceedings
    a OCS Study MMS 87-0017 Forage Fishes of the Southeastern Bering Sea Conference Proceedings 1-1 July 1987 Minerals Management Service Alaska OCS Region OCS Study MMS 87-0017 FORAGE FISHES OF THE SOUTHEASTERN BERING SEA Proceedings of a Conference 4-5 November 1986 Anchorage Hilton Hotel Anchorage, Alaska Prepared f br: U.S. Department of the Interior Minerals Management Service Alaska OCS Region 949 East 36th Avenue, Room 110 Anchorage, Alaska 99508-4302 Under Contract No. 14-12-0001-30297 Logistical Support and Report Preparation By: MBC Applied Environmental Sciences 947 Newhall Street Costa Mesa, California 92627 July 1987 CONTENTS Page ACKNOWLEDGMENTS .............................. iv INTRODUCTION PAPERS Dynamics of the Southeastern Bering Sea Oceanographic Environment - H. Joseph Niebauer .................................. The Bering Sea Ecosystem as a Predation Controlled System - Taivo Laevastu .... Marine Mammals and Forage Fishes in the Southeastern Bering Sea - Kathryn J. Frost and Lloyd Lowry. ............................. Trophic Interactions Between Forage Fish and Seabirds in the Southeastern Bering Sea - Gerald A. Sanger ............................ Demersal Fish Predators of Pelagic Forage Fishes in the Southeastern Bering Sea - M. James Allen ................................ Dynamics of Coastal Salmon in the Southeastern Bering Sea - Donald E. Rogers . Forage Fish Use of Inshore Habitats North of the Alaska Peninsula - Jonathan P. Houghton ................................. Forage Fishes in the Shallow Waters of the North- leut ti an Shelf - Peter Craig ... Population Dynamics of Pacific Herring (Clupea pallasii), Capelin (Mallotus villosus), and Other Coastal Pelagic Fishes in the Eastern Bering Sea - Vidar G. Wespestad The History of Pacific Herring (Clupea pallasii) Fisheries in Alaska - Fritz Funk . Environmental-Dependent Stock-Recruitment Models for Pacific Herring (Clupea pallasii) - Max Stocker.
    [Show full text]
  • Grade 3 Unit 2 Overview Open Ocean Habitats Introduction
    G3 U2 OVR GRADE 3 UNIT 2 OVERVIEW Open Ocean Habitats Introduction The open ocean has always played a vital role in the culture, subsistence, and economic well-being of Hawai‘i’s inhabitants. The Hawaiian Islands lie in the Pacifi c Ocean, a body of water covering more than one-third of the Earth’s surface. In the following four lessons, students learn about open ocean habitats, from the ocean’s lighter surface to the darker bottom fl oor thousands of feet below the surface. Although organisms are scarce in the deep sea, there is a large diversity of organisms in addition to bottom fi sh such as polycheate worms, crustaceans, and bivalve mollusks. They come to realize that few things in the open ocean have adapted to cope with the increased pressure from the weight of the water column at that depth, in complete darkness and frigid temperatures. Students fi nd out, through instruction, presentations, and website research, that the vast open ocean is divided into zones. The pelagic zone consists of the open ocean habitat that begins at the edge of the continental shelf and extends from the surface to the ocean bottom. This zone is further sub-divided into the photic (sunlight) and disphotic (twilight) zones where most ocean organisms live. Below these two sub-zones is the aphotic (darkness) zone. In this unit, students learn about each of the ocean zones, and identify and note animals living in each zone. They also research and keep records of the evolutionary physical features and functions that animals they study have acquired to survive in harsh open ocean habitats.
    [Show full text]
  • Atlantic "Pelagic" Fish Underwater World
    QL DFO - Library / MPO - Bibliothèque 626 U5313 no.3 12064521 c.2 - 1 Atlantic "Pelagic" Fish Underwater World Fish that range the open sea are Pelagic species are generally very Atlantic known as " pelagic" species, to dif­ streamlined. They are blue or blue­ ferentiate them from "groundfish" gray over their backs and silvery­ "Pelagic" Fish which feed and dwell near the bot­ white underneath - a form of tom . Feeding mainly in surface or camouflage when in the open sea. middle depth waters, pelagic fish They are caught bath in inshore travel mostly in large schools, tu. n­ and offshore waters, principally with ing and manoeuvring in close forma­ mid-water trawls, purse seines, gill tion with split-second timing in their nets, traps and weirs. quest for plankton and other small species. Best known of the pelagic popula­ tions of Canada's Atlantic coast are herring, but others in order of economic importance include sal­ mon, mackerel , swordfish, bluefin tuna, eels, smelt, gaspereau and capelin. Sorne pelagic fish, notably salmon and gaspereau, migrate from freshwater to the sea and back again for spawning. Eels migrate in the opposite direction, spawning in sait water but entering freshwater to feed . Underwater World Herring comprise more than one­ Herring are processed and mar­ Atlantic Herring keted in various forms. About half of (Ctupea harengus) fifth of Atlantic Canada's annual fisheries catch. They are found all the catch is marketed fresh or as along the northwest Atlantic coast frozen whole dressed fish and fillets, from Cape Hatteras to Hudson one-quarter is cured , including Strait.
    [Show full text]
  • Vii Fishery-At-A-Glance Night Smelt Scientific Name: Spirinchus Starksi Range
    Fishery-at-a-Glance Night Smelt Scientific Name: Spirinchus starksi Range: Night Smelt are distributed coast-wide from southeast Alaska to Point Arguello, Santa Barbara County. Habitat: Night Smelt occur in the surf and in depths from the surface to approximately 400 feet (122 meters). Size (length and weight): Night Smelt measure less than 6 inches total length (140 millimeters) weighing to 11 grams. Males are slightly longer and heavier than females. Life span: Night Smelt are short lived and believed to reach a maximum of 2 to 3 years. Reproduction: Spawning occurs in the surf along open coast coarse sand beaches from January to September. Eggs are fertilized in the wash of the surf, adhere to sand grains, and sink. Hatching occurs in approximately 2 weeks. Prey: Night Smelt feed on small crustaceans—primarily gammarid amphipods and mysid shrimp. Predators: Night Smelt provide forage for a wide range of predators, including Striped Bass, Redtail Surfperch, salmon, Harbor Seals, California Sea Lions, terns, gulls, and cormorants. Fishery: Commercial and recreational fisheries are shore-based. Area fished: Historically, fishing occurred from Moss Landing, Monterey County to the Oregon border. Currently, fishing occurs from San Mateo County to Del Norte County. Fishing season: Fishing occurs during the spawning season—January to September. Fishing gear: Fishermen fish from shore using A-frame dip nets. Market(s): Landed fish are sold for human consumption and aquarium food. Current stock status: No formal stock assessments exist for Night Smelt. Although catch rates have increased on average since the early 2000s, it is undetermined if this increase in the index is due to increased abundance or changes in fishermen behavior.
    [Show full text]
  • Forage Fish Management Plan
    Oregon Forage Fish Management Plan November 19, 2016 Oregon Department of Fish and Wildlife Marine Resources Program 2040 SE Marine Science Drive Newport, OR 97365 (541) 867-4741 http://www.dfw.state.or.us/MRP/ Oregon Department of Fish & Wildlife 1 Table of Contents Executive Summary ....................................................................................................................................... 4 Introduction .................................................................................................................................................. 6 Purpose and Need ..................................................................................................................................... 6 Federal action to protect Forage Fish (2016)............................................................................................ 7 The Oregon Marine Fisheries Management Plan Framework .................................................................. 7 Relationship to Other State Policies ......................................................................................................... 7 Public Process Developing this Plan .......................................................................................................... 8 How this Document is Organized .............................................................................................................. 8 A. Resource Analysis ....................................................................................................................................
    [Show full text]
  • Rainbow Smelt Spawning Monitoring
    PROGRESS REPORT State: NEW HAMPSHIRE Grant: F-61-R-22/F19AF00061 Grant Title: NEW HAMPSHIRE’S MARINE FISHERIES INVESTIGATIONS Project I: DIADROMOUS FISH INVESTIGATIONS Job 2: MONITORING OF RAINBOW SMELT SPAWNING ACTIVITY Objective: To annually monitor the Rainbow Smelt Osmerus mordax resource using fishery independent techniques during their spawning run in the Great Bay Estuary. Period Covered: January 1, 2019 - December 31, 2019 ABSTRACT In 2019, a total of 844 Rainbow Smelt Osmerus mordax (349 in Oyster River, 405 in Winnicut River, and 90 in Squamscott River) were caught in fyke nets. The CPUE in 2019 was highest in the Oyster River with 23.79 smelt per day, whereas the Winnicut River (8.46 smelt per day) and Squamscott River (5.54 smelt per day) were lower. A male-skewed sex ratio was observed at all rivers, a likely result of differences in spawning behavior between sexes. The age distribution of captured Rainbow Smelt, weighted by total catch was highest for age-2 fish, followed by age-1, age-3, and age-4 fish. Most water quality measurements (temperature, dissolved oxygen, specific conductivity, and pH) were within or near acceptable ranges for smelt spawning and egg incubation and development in 2019; however, turbidity was above the threshold in the Oyster River for most days monitored. INTRODUCTION Rainbow Smelt Osmerus mordax are small anadromous fish that live in nearshore coastal waters and spawn in the spring in tidal rivers immediately above the head of tide in freshwater (Kendall 1926; Murawski et al. 1980; Buckley 1989). Anadromous smelt serve as important prey for commercial and recreational culturally valuable species, such as Atlantic Cod Gadus morhua, Atlantic Salmon Salmo salar, and Striped Bass Morone saxatilis (Clayton et al.
    [Show full text]
  • Fishes of Terengganu East Coast of Malay Peninsula, Malaysia Ii Iii
    i Fishes of Terengganu East coast of Malay Peninsula, Malaysia ii iii Edited by Mizuki Matsunuma, Hiroyuki Motomura, Keiichi Matsuura, Noor Azhar M. Shazili and Mohd Azmi Ambak Photographed by Masatoshi Meguro and Mizuki Matsunuma iv Copy Right © 2011 by the National Museum of Nature and Science, Universiti Malaysia Terengganu and Kagoshima University Museum All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means without prior written permission from the publisher. Copyrights of the specimen photographs are held by the Kagoshima Uni- versity Museum. For bibliographic purposes this book should be cited as follows: Matsunuma, M., H. Motomura, K. Matsuura, N. A. M. Shazili and M. A. Ambak (eds.). 2011 (Nov.). Fishes of Terengganu – east coast of Malay Peninsula, Malaysia. National Museum of Nature and Science, Universiti Malaysia Terengganu and Kagoshima University Museum, ix + 251 pages. ISBN 978-4-87803-036-9 Corresponding editor: Hiroyuki Motomura (e-mail: [email protected]) v Preface Tropical seas in Southeast Asian countries are well known for their rich fish diversity found in various environments such as beautiful coral reefs, mud flats, sandy beaches, mangroves, and estuaries around river mouths. The South China Sea is a major water body containing a large and diverse fish fauna. However, many areas of the South China Sea, particularly in Malaysia and Vietnam, have been poorly studied in terms of fish taxonomy and diversity. Local fish scientists and students have frequently faced difficulty when try- ing to identify fishes in their home countries. During the International Training Program of the Japan Society for Promotion of Science (ITP of JSPS), two graduate students of Kagoshima University, Mr.
    [Show full text]
  • The Soil Food Web
    THE SOIL FOOD WEB HEALTHY SOIL HEALTHY ENVIRONMENT The Soil Food Web Alan Sundermeier Extension Educator and Program Leader, Wood County Extension, The Ohio State University. Vinayak Shedekar Postdoctural Researcher, The Ohio State University. A healthy soil depends on the interaction of many organisms that make up the soil food web. These organisms live all or part of their life cycle in the soil and are respon- sible for converting energy as one organism consumes another. Source: Soil Biology Primer The phospholipid fatty acid (PLFA) test can be used to measure the activity of the soil food web. The following chart shows that mi-crobial activity peaks in early summer when soil is warm and moisture is adequate. Soil sampling for detecting soil microbes should follow this timetable to better capture soil microbe activity. The soil food web begins with the ener- gy from the sun, which triggers photo- synthesis in plants. Photosynthesis re- sults in plants using the sun’s energy to fix carbon dioxide from the atmosphere. This process creates the carbon and organic compounds contained in plant material. This is the first trophic level. Then begins building of soil organic matter, which contains both long-last- ing humus, and active organic matter. Active organic matter contains readily available energy, which can be used by simple soil organisms in the second trophic level of the soil food web. Source: Soil Biology Primer SOILHEALTH.OSU.EDU THE SOIL FOOD WEB - PAGE 2 The second trophic level contains simple soil organisms, which Agriculture can enhance the soil food web to create more decompose plant material.
    [Show full text]
  • HOLT Earth Science
    HOLT Earth Science Directed Reading Name Class Date Skills Worksheet Directed Reading Section: What Is Earth Science? 1. For thousands of years, people have looked at the world and wondered what shaped it. 2. How did cultures throughout history attempt to explain events such as vol- cano eruptions, earthquakes, and eclipses? 3. How does modern science attempt to understand Earth and its changing landscape? THE SCIENTIFIC STUDY OF EARTH ______ 4. Scientists in China began keeping records of earthquakes as early as a. 200 BCE. b. 480 BCE. c. 780 BCE. d. 1780 BCE. ______ 5. What kind of catalog did the ancient Greeks compile? a. a catalog of rocks and minerals b. a catalog of stars in the universe c. a catalog of gods and goddesses d. a catalog of fashion ______ 6. What did the Maya track in ancient times? a. the tides b. the movement of people and animals c. changes in rocks and minerals d. the movements of the sun, moon, and planets ______ 7. Based on their observations, the Maya created a. jewelry. b. calendars. c. books. d. pyramids. Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Earth Science 7 Introduction to Earth Science Name Class Date Directed Reading continued ______ 8. For a long time, scientific discoveries were limited to a. observations of phenomena that could be made with the help of scientific instruments. b. observations of phenomena that could not be seen, only imagined. c. myths and legends surrounding phenomena. d. observations of phenomena that could be seen with the unaided eye.
    [Show full text]
  • Urban Food Webs: Predators, Prey, and the People Who Feed Them
    Urban Food Webs: Predators, Prey, and the People Who Feed Them A prevailing image of the city is of the steel and ships and energy flows through natural habitats, they concrete downtown skyline. The more common ex‑ have not been applied to urban ecosystems until re‑ perience of urban residents, however, is a place of cently (Faeth et al. 2005). irrigated and fertilized green spaces, such as yards, gardens, and parks, surrounding homes and business‑ At a symposium presented at the 2006 Ecological es where people commonly feed birds, squirrels, and Society of America meeting, 10 speakers assembled other wildlife. Within these highly human-modified to present and discuss “The Urban Food Web: How environments, researchers are becoming increasingly Humans Alter the State and Interactions of Trophic curious about how fundamental ecological phenom‑ Dynamics,” in a symposium organized by Paige War‑ ena play out, such as the feeding relationships among ren, Chris Tripler, Chris Lepczyk, and Jason Walker. species. While food webs have long provided a tool A key feature of urban environments, as described in for organizing information about feeding relation‑ the symposium, is that human influence may be en‑ Fig. 1. A generalized model of trophic dynamics in urban vs. non-urban terrestrial systems (modified from Faeth et al. 2005). Humans alter both systems, but in urban environments, human influences are more profound and include (a) enhancement of basal resources like water and fertilizer, and (b) direct control of plant species diversity and primary productivity, leading to strong bottom-up controls. Humans also (c) directly subsidize resources for herbivores and predators either through intentional feeding or unintended consequences of other activities (e.g., garbage, landscape plantings), leading to enhanced top-down control for some taxa and reduced top-down controls on others (see Fig.
    [Show full text]