Rocky+Intertidal+Zone+(Autotrophs)

Autotrophs of the Rocky Intertidal Zone  By Zechariah Franks, Jessica Morgan, Brittany Dickinson, Rusty Leach, Ashley Guard

Table of Contents
 * 1) What and Where is the Rocky Intertidal?
 * 2) Abiotic Characteristics
 * 3) Biotic Characteristics of Autotrophs
 * 4) Green Algae
 * 5) Red Algae
 * 6) Brown Algae
 * 7) Sea Grasses
 * 8) Man's Impact on the Autotrophs of the Rocky Intertidal
 * 9) References

1. What and Where is the Rocky intertidal?  The rocky Intertidal needs two basics elements to exist - Ocean water and rocks for the ocean water to get trapped in. As ocean tide rolls in and out, water gets trapped in the small crevices along with any organisms that are amongst it. Many organisms like algaes or echinoderms are swept into theses pools by the ocean tides and planted amongst the moist rocky substrate. At times of high tide, the tide pools of the rocky intertidal can be completely submerged and any hint of life is hard to see. But when the tide rolls out and all of the shallow pools are exposed and its easy to see the pools bursting with life.

Tide pools are unique ecosystems because they are both separated from the ocean and connected to it on a daily basis. It takes a well adapted organism to be able to thrive in such constant changes. Due to these unique characteristics, a diverse and unique assortment of algaes will develop in these pools.  The rocky intertidal can be found anywhere the ocean meets the coast with the two basic elements mentioned above. Specifically on the Pacific coast, this usually occurs along the cliff and rock covered coasts of the north. As you approach places in south, sandy beaches are more prominent and rocky tide pools are rare and spread out.



2. Abiotic Characteristics The two major abiotic components of the Rocky Intertidal are the movement of the tides and the the rocky substrates. Without these two things, the unique and dynamic environment would not exist. If the tides did not continuously submerge and end expose the rocky substrate, the ecosystem would either be continuously exposed to the open ocean or it would have no moisture at all. If this were true, the competition for substrate would increase dramaticallu because species would not have to be adapted to these abiotic conditions.

Another abiotic influence on this ecosystem is the crashing waves. The constant turbulence of crashing waves on the rocky substrate can greatly affect was type of organisms grow there. It is more often that alages have difficulties attaching to these substrates and are better maintained in more protected and less turbulent areas of the tidepool. These portions are often dominated by heterotrophs such as mussels and barnacles.

To better identify the organisms within the intertidal zone, it is broken up into 4 physically separate zones:

Splash Zone - is the uppermost region and is mostly exposed to air with relatively little moisture. Green algae often dominates this zone. High Intertidal - Is exposed to the air a relatively long period of time for about twice a day. Brown algae are consistently seen here. Mid Intertidal - Is exposed to air briefly twice a day and is usually dominated by red algae. High Intertidal - Is exposed to air only at the lowest tides, but it often submerges. Red and brown algaes are present here.



3. Biotic Characteristics of Autotrophs

There are 4 groups of autotrophic organisms that dominate the intertidal zone. There is green algae, red algae, brown algae, and sea grasses. The following descriptions are given to provide information on the major characteristics of these groups inside and outside the roc ky inte rtidal zone.  **3.1 Green Algae**  Green algae are the most diverse of all algae’s. There are more than 7,000 known species of green algae 13]. Green algae contain chlorophyll a and b 14]. They use chlorophyll to capture light energy to produce sugar. //Chlorophyta// is most abundant in warmer waters and is most plentiful in the shallower intertidal zones. T his is because they are able to absorb light better 14]. The phylum //Chlorophyta// is in the Kingdom //Protista//. Green algae can be unicellular, multicellular, coenocytic, or colonial 15]. Small, motile Chlorophyta have flagella, which help them move around. Green algae have cells, called chloroplast that allows for photosynthesis to occur. They store their food as starch 15].
 * Green Algae: //Chlorophyta// **

There are more than 7,000 species of green algae 13]. Each species is extremely helpful to the environment. The following are examples of Chlorophyta: //Chaetomorpha aerea// and //Ulva ssp// 16]. // Chaetomorpha aerea: // Often found on rocks, in areas near tide pools, //Chaetomorpha aerea// lives in the mid to high intertidal zones. It is most common from the Gulf of California to Southern British Columbia. //Chaetomorpha// //aerea// is about 5-30 centimeters long 16].  // Ulva spp.: // <span style="font-family: Arial,Helvetica,sans-serif;">The common name for //Ulva spp.// is Sea Lettuce. It is often found from Alaska to Mexico in the mid to low intertidal zones. It is only about 2 cell layers thick, so it appears transparent. Sea lettuce is often used for food. Many people use it in salads, soups, and a variety of other food dishes 16].

<span style="font-family: Arial,Helvetica,sans-serif;"> **3.2 Red Algae** <span style="font-family: Arial,Helvetica,sans-serif;"> <span style="font-family: Arial,Helvetica,sans-serif;"> Red algae is marine algae also known as //Rhodophyta.// In this specific type of algae, the chlorophyll masked by a red or purplish pigment, which is where it gets its red tint. Red algae are almost always marine and include many important species that are both edible and economical. 4]. Unusual among the algaes because they can include their cell walls calcium carbonate which makes the plants hard and resistant to wear.<span style="font-family: Arial,Helvetica,sans-serif;">

Red algae range from microscopic forms to large fleshy algae. They are usually red but some species living high on the intertidal fringe may appear to be olive-brown. Some encrusting forms are pink or white. The red algae group can be distinguished by features such as eukaryotic cells without flagella and centrioles, using flordian starch as food reserve, with phycolbiliproteins as accessory pigments, and with chloroplasts lacking external endoplasmic reticulum and containing unstaked thylakoids. 9] <span style="font-family: Arial,Helvetica,sans-serif;"> There are around 6,500 to 10,000 known species, almost all of which are marine and about 200 that only live in <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;"> fresh water. Red algae are the largest and most intricate of the seaweeds.5] <span style="font-size: 90%; color: rgb(0, 0, 0); font-family: Arial,Helvetica,sans-serif;"> <span style="font-family: Arial,Helvetica,sans-serif;"> They do not have flagellated cells, are structurally complex, and have complex life cycles divided <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;">into three phases. Those three phases include: tetrasporophyte, gametophyte and carposporophyte. 6] <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;"> Red algae are found in all the regions of the world. They are attached to bottom or other har <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;">d surface <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;">s, <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;">and are of <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;">ten most conspicuous in the intertidal region of rocky coasts and in tide pool <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; color: rgb(0, 0, 0);"> <span style="font-family: Arial,Helvetica,sans-serif;">s. In the tropics they are found in all zones of the coral reef. The larger species usually grow attached to a hard substrate, or they occur as epiphytes on other algae. 7]

Some red algaes also have been known to be economically important as well. They are either used as food or as manufactorers of lesser products used in the food and drug industries. 8]<span style="color: rgb(51, 51, 51);"> <span style="font-family: Arial,Helvetica,sans-serif;"><span style="font-family: Arial,Helvetica,sans-serif;">

**3.3 Brown Algae** There are roughly 1,500 species of brown algae, and almost all are found in marine environments. They are members of the class phaeophycae, and<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> are common in cold water. Fresh water species are rare. Their color ranges from a dark brown to an olive green. Brown algae can reproduce both sexually and asexually. Like other algaes, brown algaes have holdfasts, which act similar to a root, and allow them to secure themselves to rocks to keep from being washed away. They bind to rocky substrates, like Rockweed for example, or they can float freely like sargassum.<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> 12] Many brown algae are still an important source of algin, a colloidal gel used as a stabilizer in the baking and ice cream industries, according to the Encyclopedia Britannica 10]. Kelps are brown algae. They range in size from 1 meter to over 100 meters, or about 3.3 feet u<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> p to 330 feet! Some such species are laminaria, macrocystis, and nerocystis. Bull kelp washed up on shore is also a brown alae. Often their holdfasts are chewed away by urchins on the rocks below, setting them loose, where they eventually wash up on the beach. Other brown algaes are pelvita, and the boa kelp egregia<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;">. <span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> Some kinds of fucus, like fucus spiralis and fucus distichus have elongated tips which serve as reproductive tissues, cont<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> a<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> ining either eggs or sperm. This is different than brown algae that has small air pockets on the tips to keep it afloat. Such pockets ensure that the plant<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> can r<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> e<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> ach for the surface, collecting sunlight energy for photosynthesis.Fucus and laminaria are commonly used in beauty products that fight aging and cellulit<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> e.Brown algae are ten times richer in trace elements than land plants. 11]<span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;">

**3.4 Sea Grasses**


 * What are Seagrasses?**

Seagrasses are simply grasses and other flowering plants that live in shallow ocean water. They, like most land plants, produce their own energy by photosynthesizing. They also produce oxygen to help in the stabilization of intertidal shores. They form beds that attach to rocks within high-energy, low intertidal and shallow subtidal <span style="font-weight: normal; color: rgb(0, 0, 0); font-family: Times New Roman;"> habitats by short roots that form mats often covered by sand. There are four different kinds or families of seagrasses: //Posidoniaceae//, //Zosteraceae//, //Hydrocharitaceae//, and //Cymodoceaceae//. All of these grow in oceanic marine environments (fully-saline). One of the reasons why they are called seagrasses is because of the long and narrow blades that are often green. Another reason is because they grow in “meadows” which imitate grasslands. Due to their need to photosynthesize they are limited to depths that allow for the best degree of sunlight. Seagrasses are not limited to mono-specific growth, they can grow in multi-specific environments, whereas two or more species of seagrass co-exist in a bed or meadow. 1]


 * Surfgrass**

Surfgrass is a common species of seagrass found on California’s Coast. On much of California’s sand-influenced shores, surfgrass dominates. The sand accumulation has appeared to enhance its growth. Besides the contribution of fresh oxygen within ecosystem it lives in, another common use for the surfgrass is the composition of invertebrate communities that form, gather, and live within these beds and meadows. Some common members of this community include: Surfgrass Limpets, multiple species of Lacuna, Anemone, Turban Snails, and small fish such as the Garibaldi. Because this grass and all the other grasses are autotrophs they are critical to the food web. Many species are dependent either directly or indirectly on these grasses. Some of them include: sea turtles, manatees, some waterfowl, snails, urchins, lobsters, crabs, scallops, jellyfish, sea anemones, flounder, and other fish species. 2]

Eelgrass or //Zostera// is also found on sandy substrates in marine environments either submerged or partially floating. Eelgrass, much like surfgrass, is important for stabilizing the substrate ecosystem, is a living habitat for many small animals and many species of small fish, and is also important for deposition of sediment. Not many animals eat eelgrass due to its high cellulose content. Most animals cannot digest cellulose, but the Brent Geese and Wigeon do graze on eelgrass.
 * Eelgrass**

Eelgrass flourishes in environments that have fluctuations in osmolarity. Due to its ability to gain or lose solutes as the tide goes in or out, it is able to maintain its turgor at a constant pressure. 3]

Some of the inherent dynamics of seagrass ecosystems are storms, ice-scouring, grazing, and desiccation. The constant beating of the ocean waves also play an important and dynamic influence on seagrasses. 1]
 * Natural Disturbances**

The most noticeable human disturbance is eutrophication, overfishing, and mechanical destruction. These three disturbances are the main reason for the global decline of seagrasses in the last decade. Nitrogen and Phosphorus are toxic to seagrasses in excess. These two overstimulate macro and micro algae causing an over-excessive growth which covers more ground resulting in less sunlight able to reach the grasses. Algal blooms are caused by many things including decaying seagrass blades resulting in a positive feedback. There can be shifts of seagrass and algal dominance in areas of constant change. 1]
 * Human Disturbances**

Some sandy soil fertilizer is made from seagrasses. In the early part of the 20th Century the French and Channel Islands used it as filling for mattresses. During the first World War it was in high demand by the French. Today, it is used for woven material and furniture. In the past over-harvesting in some areas have caused a problem with seagrass growth, but today more care is taken to help preserve these ecosystems. 3]
 * Uses for Seagrasses**

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 * 4. Man's Impact on the Autotrophs of the Rocky Intertidal Zone **

<span style="font-family: Arial,Helvetica,sans-serif;">The rocky intertidal zone is a delicate place, and should be treated as such. In his book 'Between Pacific Tides', Ed Ricketts talks about the frailty of the marine habitat, especially on the rocky shores where two-legged visitors and collectors can have serious effects. For example, collecting shells and other marine life may seem harmless, but can severely interupt the life cycles of these species, which in turn effect other species. Autotrophs are no different. The most pervasive problem faced by autotrophs is the presence of visitors to the beach who step all over the algae, never thinking that the plants they tread on are alive and are a key part of the habitat. Other factors include oil spillage, toxic runoff from city drains, housing development, fishing and more vacationers. All these factors can spell out disaster for the intertidal autotrophs and the numerous species they support. For example, if toxic runoff is absorbed by autotrophs, or even simply coats the smooth skin of kelp and algae, smaller organisms can become intoxicated by consuming the algae, which may lead to more toxicity farther down the food chain. Also, the introduction of foreign species can have dramatic effects on intertidal autotrophs; some native species of snail have become hard pressed for their claim to the intertidal zone after snails from Japan, which hitched rides over on ships, have begun to compete for food and habitat. This just goes to show that everything is interconnected, and that the autotrophs of the intertidal zone are constantly facing pressures from all sides. 12]

5. References [1] [] [2] [] [3] [] [4] <span style="font-size: 81%; font-family: Arial,Helvetica,sans-serif;"> Red Algae. (2009). //Absolute Astronomy//. Retrieved March 30, 2009, from[| http://www] <span style="font-size: 81%; font-family: Arial,Helvetica,sans-serif;"> [|.absoluteastronomy.com/topics/Red_algae] [5] Algae. (2008). //Biology Encyclopedia//. Retrieved March 30, 2009, from [| www.biologyreference.com/A-Ar/Algae.html] [6] <span style="font-size: 72.9%; font-family: Arial,Helvetica,sans-serif;"> Parmentier, J. (1999, March). POLYSIPHONIA: A Red Algae. In //Micscape Magazine//. Retrieved March 30,2009, from http://www.microscopyuk.org.uk/mag/indexmag.html?http:www.microscopyuk.org.uk/mag/artmar99/red.html [7] <span style="font-size: 8.748pt; font-family: Arial,Helvetica,sans-serif;"> Algae - Algae And Their Characteristics, Types Of Algae, Ecological Relationships, Factors Limiting The Productivity Of Algae. (2009). Science Encycl <span style="font-size: 81%; font-family: Arial,Helvetica,sans-serif;"> opedia. Retrieved March 30, 2009, from [|http://science.jrank.org/pages/205/Algae.html] [8] R  hodophyta. (n.d.). Botany Projects. Retrieved March //30, 2009,// [] [9] <span style="font-size: 90%; font-family: Arial,Helvetica,sans-serif;"> //Wilson Freshwater, D. (2000). Rhodophyta. In// Tree of Life Web Projects//. Retrieved March 30, 2009, [] [10] [] [11] []. [12] Rick <span style="font-size: 72.9%; font-family: Arial,Helvetica,sans-serif;"> etts, Edward F. 1985. Between Pacific Tides. Stanford, CA: Stanford University Press. [13] <span style="color: rgb(51, 51, 51);">"Introduction to the "Green Algae" < [] >. <span style="font-size: 10pt; color: rgb(51, 51, 51); font-family: Arial;">  [14] <span style="color: rgb(51, 51, 51);">" Green Algae - Chlorophyta." < [] >.   [15] <span style="font-size: 10pt; color: rgb(51, 51, 51); font-family: Arial;"> <span style="color: rgb(51, 51, 51);">" <span style="background: rgb(220, 238, 255) none repeat scroll 0% 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">Chlorophyta  ." __The Columbian Encyclopedia__. 6th ed. 2008. The Columbian __Encyclopedia__. 20 Apr. 2009 < [] >. [16] <span style="color: rgb(51, 51, 51);">Mondragon  <span style="color: rgb(51, 51, 51);">, Jennifer, and Jeff Mondragon. Seaw  <span style="font-size: 10pt; color: rgb(51, 51, 51); font-family: Arial;"> <span style="font-size: 8pt; font-family: Arial; color: rgb(51, 51, 51);"> eeds __of the Pacific Coast__. Santa Rosa : Global Interprint, 2003**.** <span style="font-size: 8.748pt; font-family: Arial,Helvetica,sans-serif;"> <span style="font-size: 10pt; color: rgb(51, 51, 51); font-family: Arial;"> <span style="font-size: 90%; font-family: Arial,Helvetica,sans-serif;"> <span style="font-size: 81%; font-family: Arial,Helvetica,sans-serif;"> <span style="font-size: 90%; font-family: Arial,Helvetica,sans-serif;">  <span style="font-size: 90%; font-family: Arial,Helvetica,sans-serif;"> <span style="font-size: 72.9%; font-family: Arial,Helvetica,sans-serif;"> <span style="font-size: 90%; font-family: Arial,Helvetica,sans-serif;">  <span style="font-size: 90%; font-family: Arial,Helvetica,sans-serif;">  <span style="font-size: 10pt; color: rgb(51, 51, 51); font-family: Arial;"> <span style="font-size: 10pt; color: rgb(51, 51, 51); font-family: Arial;"> <span style="font-size: 10pt; color: rgb(51, 51, 51); font-family: Arial;">