Ecological succession describes how communities change over time as earlier species are replaced by later species that are better adapted. Dredging disturbs benthic habitats by removing and disposing of sediments, potentially resetting ecological succession. The sediments dumped after dredging can smother existing organisms, impact species during reproduction, and contain toxic contaminants that can harm eggs, larvae, and coral reefs. Proper disposal methods aim to isolate contaminants and prevent their spread, such as capping sites or dredging in a way that buries more polluted sediments.
Hurricanes form over warm ocean waters between 15 and 200 latitude from the equator when low pressure systems allow warm, humid air to rise and condense. They have a circular structure with counterclockwise spinning winds in the Northern Hemisphere that can be hundreds of miles wide. Hurricanes strengthen over warm ocean waters but weaken when making landfall or interacting with strong upper level winds or cooler waters. They can cause extensive wind damage, flooding from heavy rains, and storm surges that become especially destructive during high tides.
This document provides a brief history of notable figures and expeditions that advanced ocean exploration from the 1500s to present day. It describes Portuguese explorer Ferdinand Magellan's leadership of the first voyage to circumnavigate the globe in the 1500s. In the 1700s, Benjamin Franklin mapped the Gulf Stream current. Charles Darwin in the early 1800s described how coral reefs form and introduced the theory of natural selection. The multi-year Challenger Expedition in the late 1800s conducted the first truly oceanographic research cruise. More recent pioneers include Jacques Cousteau who developed modern SCUBA gear and Sylvia Earle who is a renowned marine biologist and conservationist.
Impacts of Temperature and Salinity on Marine Animalsmswilliams
Marine animals are either ectothermic or endothermic, with ectothermic animals like fish having body temperatures dependent on their environment while endothermic animals like mammals and birds can regulate their internal temperatures. All marine animals also must regulate salt levels in their bodies through osmoregulation as temperature and salinity of water can impact animals' physiology and survival.
Plankton are tiny organisms that drift or float in the waters of seas, lakes, and rivers. They can be either autotrophs, which produce their own food through photosynthesis (phytoplankton like diatoms and dinoflagellates), or heterotrophs, which consume other organisms for food (zooplankton like tiny crustaceans). Phytoplankton are the base of the oceanic food web and are found in the photic zone where there is enough sunlight for photosynthesis. Some phytoplankton can bloom rapidly and be dangerous. Plankton play an important role in marine ecosystems.
Introduction to biological oceanography notesmswilliams
This document provides an introduction to key concepts in biological oceanography, including evolution, causes of evolution, and evidence of evolution. It defines evolution as change over time that occurs between species through processes like mutation, genetic drift, gene flow, natural selection, and non-random mating. The document also discusses concepts like overproduction, competition, genetic variation, adaptation, natural selection, speciation, classification, and the criteria used to place organisms into kingdoms.
This document summarizes three groups of marine flowering plants: seagrasses, mangroves, and salt marsh grasses. Seagrasses grow in coastal waters and reproduce both sexually and asexually. Mangroves are woody trees found in tropical and subtropical intertidal zones that reproduce sexually. Salt marsh grasses are found along coasts and reproduce sexually and asexually. All three play an important role as nursery habitats for young marine organisms.
This document provides information about marine algae. It describes the different parts of an algae's thallus including the holdfast, blade, and stipe. It notes that algae can have air bladders to assist with buoyancy. It states that algae are autotrophs that belong to the kingdom Protista or Plantae. There are three main types of algae - green algae, red algae, and brown algae - which differ in their pigments, habitats, and examples. It compares key differences between algae and land plants such as their access to water, support structures, anchoring mechanisms, and reproductive organs.
Ecological succession describes how communities change over time as earlier species are replaced by later species that are better adapted. Dredging disturbs benthic habitats by removing and disposing of sediments, potentially resetting ecological succession. The sediments dumped after dredging can smother existing organisms, impact species during reproduction, and contain toxic contaminants that can harm eggs, larvae, and coral reefs. Proper disposal methods aim to isolate contaminants and prevent their spread, such as capping sites or dredging in a way that buries more polluted sediments.
Hurricanes form over warm ocean waters between 15 and 200 latitude from the equator when low pressure systems allow warm, humid air to rise and condense. They have a circular structure with counterclockwise spinning winds in the Northern Hemisphere that can be hundreds of miles wide. Hurricanes strengthen over warm ocean waters but weaken when making landfall or interacting with strong upper level winds or cooler waters. They can cause extensive wind damage, flooding from heavy rains, and storm surges that become especially destructive during high tides.
This document provides a brief history of notable figures and expeditions that advanced ocean exploration from the 1500s to present day. It describes Portuguese explorer Ferdinand Magellan's leadership of the first voyage to circumnavigate the globe in the 1500s. In the 1700s, Benjamin Franklin mapped the Gulf Stream current. Charles Darwin in the early 1800s described how coral reefs form and introduced the theory of natural selection. The multi-year Challenger Expedition in the late 1800s conducted the first truly oceanographic research cruise. More recent pioneers include Jacques Cousteau who developed modern SCUBA gear and Sylvia Earle who is a renowned marine biologist and conservationist.
Impacts of Temperature and Salinity on Marine Animalsmswilliams
Marine animals are either ectothermic or endothermic, with ectothermic animals like fish having body temperatures dependent on their environment while endothermic animals like mammals and birds can regulate their internal temperatures. All marine animals also must regulate salt levels in their bodies through osmoregulation as temperature and salinity of water can impact animals' physiology and survival.
Plankton are tiny organisms that drift or float in the waters of seas, lakes, and rivers. They can be either autotrophs, which produce their own food through photosynthesis (phytoplankton like diatoms and dinoflagellates), or heterotrophs, which consume other organisms for food (zooplankton like tiny crustaceans). Phytoplankton are the base of the oceanic food web and are found in the photic zone where there is enough sunlight for photosynthesis. Some phytoplankton can bloom rapidly and be dangerous. Plankton play an important role in marine ecosystems.
Introduction to biological oceanography notesmswilliams
This document provides an introduction to key concepts in biological oceanography, including evolution, causes of evolution, and evidence of evolution. It defines evolution as change over time that occurs between species through processes like mutation, genetic drift, gene flow, natural selection, and non-random mating. The document also discusses concepts like overproduction, competition, genetic variation, adaptation, natural selection, speciation, classification, and the criteria used to place organisms into kingdoms.
This document summarizes three groups of marine flowering plants: seagrasses, mangroves, and salt marsh grasses. Seagrasses grow in coastal waters and reproduce both sexually and asexually. Mangroves are woody trees found in tropical and subtropical intertidal zones that reproduce sexually. Salt marsh grasses are found along coasts and reproduce sexually and asexually. All three play an important role as nursery habitats for young marine organisms.
This document provides information about marine algae. It describes the different parts of an algae's thallus including the holdfast, blade, and stipe. It notes that algae can have air bladders to assist with buoyancy. It states that algae are autotrophs that belong to the kingdom Protista or Plantae. There are three main types of algae - green algae, red algae, and brown algae - which differ in their pigments, habitats, and examples. It compares key differences between algae and land plants such as their access to water, support structures, anchoring mechanisms, and reproductive organs.
This document discusses different types of waves, including their causes, characteristics, and behaviors. It defines key wave terminology like crest, trough, wavelength, and period. Wave size is determined by wind strength, duration, and fetch. Deep water waves travel in orbits while shallow water waves feel the bottom and change shape as they reach shore. Breakers come in spilling, plunging, and surging types. Longshore currents move sand along beaches, while rip currents pull water back out to sea. Tsunamis and rogue waves present unique wave hazards.
This document summarizes key concepts regarding fisheries management. It defines important terms like fish stocks, exclusive economic zone (EEZ), and mechanisms for harvesting fish. It discusses challenges like bycatch, overfishing, and factors contributing to declining fish populations. Strategies for conservation are outlined, such as gear restrictions, catch limits, and protecting essential fish habitat. The document also reviews agencies and laws involved in fisheries management, such as the Magnuson-Stevens Act and its goals of preventing overfishing while achieving sustainable yields.
Most life in the oceans depends on sunlight that autotrophs are able to capture through pigments to photosynthesize and produce food. Different pigments absorb different wavelengths of light, allowing autotrophs to live at varying depths where certain wavelengths penetrate deepest. The rate of photosynthesis must exceed the rate of respiration for phytoplankton to survive, setting a compensation depth above which they can thrive. Coastal waters often have higher turbidity than the open ocean due to sediment and inputs that cloud the water and limit sunlight penetration.
Some equipment used by chemical oceanographersmswilliams
This document describes several pieces of equipment used by chemical oceanographers to sample and measure various water parameters. It discusses Niskin and Nansen bottles, rosettes, thermometers, hydrometers, refractometers, CTDs, Secchi disks, DO meters, SONAR, and side scan SONAR, and provides brief explanations of how each tool is used.
The document summarizes the chemical composition of seawater. It states that seawater is mostly water, but also contains all naturally occurring elements on Earth. The main ions found in seawater are 55% chloride, 31% sodium, 8% sulfate, 4% magnesium, and 1% each of calcium and potassium. These ratios remain relatively constant in oceans around the world according to the law of constant proportions. Exceptions can occur where rivers meet the sea since river water contains more calcium. Salt enters the oceans through weathering that carries eroded rocks and minerals into rivers and seas, and also through underwater volcanic vents. Salt is removed through sea spray, sediment deposits that bind minerals, and biological activity of marine life.
Salinity refers to the concentration of dissolved ions in water, measured in parts per thousand (‰). Average ocean salinity is 35‰ but it varies depending on evaporation, precipitation, and water sources. Salinity is higher in enclosed seas like the Red Sea (40‰) and Mediterranean Sea (38‰) due to limited freshwater input and high evaporation. It is lower in semi-enclosed seas connected to oceans by narrow straits, like the Black Sea (18‰) and Baltic Sea (8‰), which receive more freshwater from rivers. Temperature, pressure, and density can also impact ocean salinity.
Water is a polar molecule with slightly positively and negatively charged ends, allowing it to form hydrogen bonds between molecules. This polarity gives water properties of adhesion, sticking to other substances, and cohesion, sticking to other water molecules. Water has relatively low viscosity and density compared to other liquids, with density highest at 4°C and lower in seawater due to salt content. Its solid form, ice, floats due to having a less dense crystalline structure. Water also has a high specific heat capacity, requiring a lot of energy to change its temperature, which allows oceans to act as a heat buffer for the planet.
The document discusses plate tectonics and describes how convection currents in the asthenosphere cause tectonic plates to move horizontally at the surface. There are three types of plate boundaries: divergent boundaries where plates move apart and new seafloor is created, convergent boundaries where plates move together and seafloor is destroyed forming trenches and volcanic islands, and transform boundaries where plates slide past each other forming faults. Examples given are the San Andreas fault and the Ring of Fire around the Pacific plate.
The document describes different zones of the ocean based on depth.
The Neritic Zone extends from the shoreline to depths of less than 200 meters over the continental shelf. The Oceanic Zone is the area beyond 200 meters depth and further offshore. The Photic Zone, also known as the Euphotic Zone, extends from the surface to a depth of around 200 meters where sunlight is available for photosynthesis. Below the Photic Zone are the Disphotic Zone from 200-1000 meters with low light, and the Aphotic Zone below 1000 meters with no light.
There are 8 species of sea turtles that visit areas like Long Island, including the Kemp's Ridley turtle, which is the most endangered with only 400-500 individuals remaining today from a population of 42,000 in 1947. Sea turtles have a three-chambered heart, scales, and lay eggs on land that incubate for around 2 months before hatchlings head to the water. They face numerous threats including humans, predators, habitat loss, and getting caught in fishing nets or ingesting plastic waste which has led to all species being endangered or threatened.
Whales evolved from land mammals and are related to horses and sheep. They have adaptations like blubber for insulation and temperature regulation, blowholes for breathing, and streamlined bodies. Whales communicate using echolocation and songs, have excellent hearing, and can slow their heart rates while diving. There are two main types of whales: toothed whales that hunt for food and baleen whales that filter feed krill. Whaling nearly wiped out many whale species until laws like the Marine Mammal Protection Act and International Whaling Commission were passed to regulate and protect whales.
This document discusses the diversity of body shapes and tail fin morphologies in fish and how these adaptations help fish survive in their environments. It describes the main body shapes as fusiform for fast open water swimmers, compressiform for quick bursts of speed, and depressiform for bottom-dwelling fish. It also outlines different tail fin shapes including homocercal forms that are rounded, truncate, forked, or lunate and the heterocercal tail of sharks, and explains how each tail type relates to the fish's swimming ability, speed, maneuverability and environment.
This document provides an overview of arthropods, which are segmented invertebrates with jointed appendages and an external skeleton. It describes their anatomy, including a chitinous exoskeleton, jointed limbs, segmented bodies, and open circulatory and nervous systems. Arthropods reproduce through external fertilization and development of planktonic larvae. The phylum includes two subphyla: chelicerates like sea spiders and horseshoe crabs, and crustaceans such as lobsters, crabs, shrimp, and barnacles. Arthropods are mostly benthic or epifaunal and found worldwide, representing the largest number of species on Earth.
Crustaceans are arthropods in the subphylum Crustacea and include crabs, shrimp, lobsters, barnacles, copepods, krill, isopods, and amphipods. They have a jointed exoskeleton and specialized appendages for locomotion, feeding, breathing through gills, and sensing the environment. Crustaceans can be predators, scavengers, or filter feeders. They have separate sexes and males release sperm packets for females to store until fertilizing their eggs, which hatch externally.
This document provides instructions for a sea star dissection lab where students are tasked with labeling the external and internal structures of a sea star using letter identifiers on diagrams. The external structures include the aboral and oral sides as well as full anatomy diagrams. Internal structures cover the digestive system, reproductive system, and water vascular system.
Echinoderms are radially symmetrical marine invertebrates found worldwide in both shallow waters and oceans. They reproduce through external fertilization and have planktonic larvae that are bilaterally symmetrical, unlike the pentamerous radial symmetry seen in adults. Echinoderms move slowly using tube feet and have an endoskeleton, with major classes including sea stars, sea urchins, sand dollars, brittle stars, sea cucumbers, and feather stars.
The document summarizes key information about bivalves, including their anatomy, habitat, feeding, reproduction, pearl formation, and internal anatomy. Bivalves have two shells held together by adductor muscles, gills for oxygen intake from water, and a mantle that secretes their shell. Most bivalves are sessile filter feeders that live on or burrow into the seafloor, though some like mussels and scallops can attach or swim. They have separate sexes and external fertilization and development. Pearls sometimes form as a protective response in oysters.
The Cephalopods are a class of mollusks that include octopuses, squid, cuttlefish, and nautiluses. They are exclusively marine animals with prominent heads, arms for feeding and locomotion, and most can expel ink. They have well-developed eyes, gills for respiration, and use jet propulsion by squeezing their bodies. They are highly adapted predators that capture prey with their arms and suckers and tear it apart with their beaks. Most reproduce through external fertilization and die after breeding.
The gastropods are an extremely diverse class of mollusks that includes snails and slugs. Most gastropods have a spiraling shell that surrounds their soft body and protects it. They have a well-defined head with ganglia but no ears, and excellent senses of smell and taste. Gastropods live on the seafloor in almost every marine environment and feed by scraping algae and decaying matter off surfaces using a rasping tongue called a radula. They reproduce through external fertilization and development.
The gastropods are an extremely diverse class of mollusks that includes snails and slugs. While many have coiled shells, some have no external shell at all. They have a well-defined head and lack ears, but have excellent senses of smell and taste. Gastropods are found in nearly every marine habitat and feed by scraping algae and decaying matter using a rasping tongue called a radula. Reproduction involves external fertilization and development of egg cases.
This document discusses different types of waves, including their causes, characteristics, and behaviors. It defines key wave terminology like crest, trough, wavelength, and period. Wave size is determined by wind strength, duration, and fetch. Deep water waves travel in orbits while shallow water waves feel the bottom and change shape as they reach shore. Breakers come in spilling, plunging, and surging types. Longshore currents move sand along beaches, while rip currents pull water back out to sea. Tsunamis and rogue waves present unique wave hazards.
This document summarizes key concepts regarding fisheries management. It defines important terms like fish stocks, exclusive economic zone (EEZ), and mechanisms for harvesting fish. It discusses challenges like bycatch, overfishing, and factors contributing to declining fish populations. Strategies for conservation are outlined, such as gear restrictions, catch limits, and protecting essential fish habitat. The document also reviews agencies and laws involved in fisheries management, such as the Magnuson-Stevens Act and its goals of preventing overfishing while achieving sustainable yields.
Most life in the oceans depends on sunlight that autotrophs are able to capture through pigments to photosynthesize and produce food. Different pigments absorb different wavelengths of light, allowing autotrophs to live at varying depths where certain wavelengths penetrate deepest. The rate of photosynthesis must exceed the rate of respiration for phytoplankton to survive, setting a compensation depth above which they can thrive. Coastal waters often have higher turbidity than the open ocean due to sediment and inputs that cloud the water and limit sunlight penetration.
Some equipment used by chemical oceanographersmswilliams
This document describes several pieces of equipment used by chemical oceanographers to sample and measure various water parameters. It discusses Niskin and Nansen bottles, rosettes, thermometers, hydrometers, refractometers, CTDs, Secchi disks, DO meters, SONAR, and side scan SONAR, and provides brief explanations of how each tool is used.
The document summarizes the chemical composition of seawater. It states that seawater is mostly water, but also contains all naturally occurring elements on Earth. The main ions found in seawater are 55% chloride, 31% sodium, 8% sulfate, 4% magnesium, and 1% each of calcium and potassium. These ratios remain relatively constant in oceans around the world according to the law of constant proportions. Exceptions can occur where rivers meet the sea since river water contains more calcium. Salt enters the oceans through weathering that carries eroded rocks and minerals into rivers and seas, and also through underwater volcanic vents. Salt is removed through sea spray, sediment deposits that bind minerals, and biological activity of marine life.
Salinity refers to the concentration of dissolved ions in water, measured in parts per thousand (‰). Average ocean salinity is 35‰ but it varies depending on evaporation, precipitation, and water sources. Salinity is higher in enclosed seas like the Red Sea (40‰) and Mediterranean Sea (38‰) due to limited freshwater input and high evaporation. It is lower in semi-enclosed seas connected to oceans by narrow straits, like the Black Sea (18‰) and Baltic Sea (8‰), which receive more freshwater from rivers. Temperature, pressure, and density can also impact ocean salinity.
Water is a polar molecule with slightly positively and negatively charged ends, allowing it to form hydrogen bonds between molecules. This polarity gives water properties of adhesion, sticking to other substances, and cohesion, sticking to other water molecules. Water has relatively low viscosity and density compared to other liquids, with density highest at 4°C and lower in seawater due to salt content. Its solid form, ice, floats due to having a less dense crystalline structure. Water also has a high specific heat capacity, requiring a lot of energy to change its temperature, which allows oceans to act as a heat buffer for the planet.
The document discusses plate tectonics and describes how convection currents in the asthenosphere cause tectonic plates to move horizontally at the surface. There are three types of plate boundaries: divergent boundaries where plates move apart and new seafloor is created, convergent boundaries where plates move together and seafloor is destroyed forming trenches and volcanic islands, and transform boundaries where plates slide past each other forming faults. Examples given are the San Andreas fault and the Ring of Fire around the Pacific plate.
The document describes different zones of the ocean based on depth.
The Neritic Zone extends from the shoreline to depths of less than 200 meters over the continental shelf. The Oceanic Zone is the area beyond 200 meters depth and further offshore. The Photic Zone, also known as the Euphotic Zone, extends from the surface to a depth of around 200 meters where sunlight is available for photosynthesis. Below the Photic Zone are the Disphotic Zone from 200-1000 meters with low light, and the Aphotic Zone below 1000 meters with no light.
There are 8 species of sea turtles that visit areas like Long Island, including the Kemp's Ridley turtle, which is the most endangered with only 400-500 individuals remaining today from a population of 42,000 in 1947. Sea turtles have a three-chambered heart, scales, and lay eggs on land that incubate for around 2 months before hatchlings head to the water. They face numerous threats including humans, predators, habitat loss, and getting caught in fishing nets or ingesting plastic waste which has led to all species being endangered or threatened.
Whales evolved from land mammals and are related to horses and sheep. They have adaptations like blubber for insulation and temperature regulation, blowholes for breathing, and streamlined bodies. Whales communicate using echolocation and songs, have excellent hearing, and can slow their heart rates while diving. There are two main types of whales: toothed whales that hunt for food and baleen whales that filter feed krill. Whaling nearly wiped out many whale species until laws like the Marine Mammal Protection Act and International Whaling Commission were passed to regulate and protect whales.
This document discusses the diversity of body shapes and tail fin morphologies in fish and how these adaptations help fish survive in their environments. It describes the main body shapes as fusiform for fast open water swimmers, compressiform for quick bursts of speed, and depressiform for bottom-dwelling fish. It also outlines different tail fin shapes including homocercal forms that are rounded, truncate, forked, or lunate and the heterocercal tail of sharks, and explains how each tail type relates to the fish's swimming ability, speed, maneuverability and environment.
This document provides an overview of arthropods, which are segmented invertebrates with jointed appendages and an external skeleton. It describes their anatomy, including a chitinous exoskeleton, jointed limbs, segmented bodies, and open circulatory and nervous systems. Arthropods reproduce through external fertilization and development of planktonic larvae. The phylum includes two subphyla: chelicerates like sea spiders and horseshoe crabs, and crustaceans such as lobsters, crabs, shrimp, and barnacles. Arthropods are mostly benthic or epifaunal and found worldwide, representing the largest number of species on Earth.
Crustaceans are arthropods in the subphylum Crustacea and include crabs, shrimp, lobsters, barnacles, copepods, krill, isopods, and amphipods. They have a jointed exoskeleton and specialized appendages for locomotion, feeding, breathing through gills, and sensing the environment. Crustaceans can be predators, scavengers, or filter feeders. They have separate sexes and males release sperm packets for females to store until fertilizing their eggs, which hatch externally.
This document provides instructions for a sea star dissection lab where students are tasked with labeling the external and internal structures of a sea star using letter identifiers on diagrams. The external structures include the aboral and oral sides as well as full anatomy diagrams. Internal structures cover the digestive system, reproductive system, and water vascular system.
Echinoderms are radially symmetrical marine invertebrates found worldwide in both shallow waters and oceans. They reproduce through external fertilization and have planktonic larvae that are bilaterally symmetrical, unlike the pentamerous radial symmetry seen in adults. Echinoderms move slowly using tube feet and have an endoskeleton, with major classes including sea stars, sea urchins, sand dollars, brittle stars, sea cucumbers, and feather stars.
The document summarizes key information about bivalves, including their anatomy, habitat, feeding, reproduction, pearl formation, and internal anatomy. Bivalves have two shells held together by adductor muscles, gills for oxygen intake from water, and a mantle that secretes their shell. Most bivalves are sessile filter feeders that live on or burrow into the seafloor, though some like mussels and scallops can attach or swim. They have separate sexes and external fertilization and development. Pearls sometimes form as a protective response in oysters.
The Cephalopods are a class of mollusks that include octopuses, squid, cuttlefish, and nautiluses. They are exclusively marine animals with prominent heads, arms for feeding and locomotion, and most can expel ink. They have well-developed eyes, gills for respiration, and use jet propulsion by squeezing their bodies. They are highly adapted predators that capture prey with their arms and suckers and tear it apart with their beaks. Most reproduce through external fertilization and die after breeding.
The gastropods are an extremely diverse class of mollusks that includes snails and slugs. Most gastropods have a spiraling shell that surrounds their soft body and protects it. They have a well-defined head with ganglia but no ears, and excellent senses of smell and taste. Gastropods live on the seafloor in almost every marine environment and feed by scraping algae and decaying matter off surfaces using a rasping tongue called a radula. They reproduce through external fertilization and development.
The gastropods are an extremely diverse class of mollusks that includes snails and slugs. While many have coiled shells, some have no external shell at all. They have a well-defined head and lack ears, but have excellent senses of smell and taste. Gastropods are found in nearly every marine habitat and feed by scraping algae and decaying matter using a rasping tongue called a radula. Reproduction involves external fertilization and development of egg cases.
The highest tides on Earth occur in the Minas Basin, the eastern extremity of the Bay of Fundy, where the average tide range is 12 meters and can reach 16 meters when the various factors affecting the tides are in phase (although the highest tides occur typically a day or two after the astronomical influences reach their peak). Although it is the gravitation of the Moon and Sun that raises the tides, the energy in the churning waters is extracted from the rotational energy of Earth spinning on its axis. Near Annapolis Royal, Nova Scotia, a tiny portion of this energy is being converted into commercial electrical energy in the only tidal power plant in the Western Hemisphere. The peak output of the Annapolis Basin generator is 20 megawatts, about 1% of Nova Scotia's electrical power capacity. --source: http://www.valleyweb.com/fundytides/
Tide going out (and coming back in) at the Government Wharf, Parrsboro, Nova Scotia --source/images: Nova Scotia Museum; see animation at: http://museum.gov.ns.ca/fossils/protect/tideanim.htm
Tides are periodic rises and falls of large bodies of water. Tides are caused by the gravitational interaction between the Earth and the Moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Since the earth is rotating while this is happening, two tides occur each day. Isaac Newton (1642 -1727) was the first person to explain tides scientifically. His explanation of the tides (and many other phenomena) was published in 1686, in the second volume of the Principia.
Spring tides are especially strong tides (they do not have anything to do with the season Spring). They occur when the Earth, the Sun , and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full moon and the new moon. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). Neap tides occur during quarter moons.
Why are they called spring and neap tides? Neap means low - so that is an easy one. Spring tides can be confusing because they have nothing to do with the season. It is not exactly known where the word 'spring' comes from in this context but there are two possible origins. One possible source is a Scandinavian word meaning to 'leap up'. Another possibility is that it is related to the natural feature of a spring - which is a place where water wells up from the earth.
ItÕs one thing to live right on the edge of the sea when big waves are crashing ashore, (Big waves, by the way, are generally caused by storm winds blowing on the ocean surface far offshore.) but add to it an extremely elevated sea level, and now those waves are breaking much higher up (and further ashore). So if there is big surf predicted for your area, and the tide charts show spring tides, you might evacuate or get those sand bags ready
Changing tides means organisms that are attached to the substrate are alternatively covered by water during high tides and exposed to air during low tides.