International Summer Water Resources Research School Dept. of Water Resources Engineering, Lund University

Ecological Function of in Xiamen Intertidal Zone and Mangrove Areas By Ida Arvidsson

2014 Ecological Function of Polychaete Animals in Xiamen Intertidal Zone Lingfeng SRS 2014

Abstract Polychaeta is a class of worms and is one of the most abundant groups of benthic animals in marine environments. Since are a crucial, basic part of marine food webs, their ecological function and contribution to marine ecosystems are of significant importance for the ecosystem services from these environments, e.g. the fishing industry. This study investigates the abundance and ecological function of polychaetes in different ecosystems. Sampling locations are the intertidal area of Huangcuo (sandy beach and rocky shore), Xiatanwei mangrove plantation and the inner lake of Yundang Lagoon, in or close to Xiamen, Fujian province. A total of 20 of polychaetes were found, with a great majority found in the Xiatanwei mangrove area. By studying the head structure of the polychaetes in the samples, the food type of each species can be predicted. From the food types of all present polychaetes, the polychaetes contribution to the food web of the sampling location can be estimated. The small number of species found at some of the sampling locations together with too little information about the food webs make it hard to draw any conclusions about the significance of polychaetes at the studied locations. Keywords: Polychaetes, Ecological Function, Intertidal zone, Mangrove, Xiamen

Student sponsored by:

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Table of Contents 1 Preface ...... 4 1.1 About the course VVRF05 and the Lingfeng Summer Research School ...... 4 1.2 Author’s Reflection ...... 4 1.3 Acknowledgements ...... 4 2 Introduction ...... 5 2.1 Problem Description ...... 5 2.2 Purpose ...... 5 3 Theory ...... 6 3.1 Polychaetes ...... 6 3.2 Sampling Locations ...... 9 4 Method ...... 11 4.1 Intertidal Zone ...... 11 4.2 Mangrove Areas ...... 12 4.3 Food Types and Ecological Function ...... 13 5 Results ...... 14 5.1 Intertidal zone ...... 14 5.2 Mangrove Areas ...... 15 5.3 Ecological Function ...... 15 6 Discussion ...... 18 7 Conclusion ...... 19 8 Bibliography ...... 20

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1 Preface

1.1 About the course VVRF05 and the Lingfeng Summer Research School This report is written as part of the course International Summer Water Resources Research School at Lund University (course code VVRF05) with the following aim: The aim is that the students should gain proficiency to work in a cross-cultural group in a foreign environment and get deepened knowledge about environment and water related issues within the framework of a minor research project. (Zhang) Students in the course participate in the Lingfeng Summer Research School which take place at the College of the Environment & Ecology at Xiamen University. The summer school is cooperation between Lund University (Sweden) and Xiamen University (China) and between 23rd of June and 18th of July 2014 the 8th summer school took place. 8 students from Lund participated 2014 and we all worked on different projects together with one or two Chinese undergraduate students studying environmental science.

1.2 Author’s Reflection To participate in the Lingfeng Summer Research School has been an interesting and important experience for me. I have had the opportunity to meet new people, make new friends and to get to know at least a part of China and Chinese culture. To work in the benthic lab has been enjoyable and I have felt very welcome in the group. I can really recommend other students to participate in the course.

1.3 Acknowledgements I wish to thank: Professor Cai Li-Zhe, postgraduates and master students in the marine benthic lab in the College of the Environment & Ecology at Xiamen University for making me feel welcome and for everything you have taught me. Associate professor Linus Zhang and the staff at the international office at Lund University and Xiamen University for the possibility of this exchange. Thyrens, Sweco Environment in Malmoe and Sveriges Ingenjörers Miljöfond for valuable financial support. I hope for further cooperation. Last but not at all least I wish to thank my project partners Liu Meichen and Wan Pengfei for your patience and care about me. I look forward to meet you again and to help you getting along when you come to Lund next spring.

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2 Introduction

2.1 Problem Description Polychaetes are among the most abundant groups of benthic animals in marine environments. Their ecological function and contribution to marine ecosystems are thereby of significant importance for the ecosystem services from these environments. Polychaetes are a crucial part of many marine food webs and thus research on this large class of animals is of great importance. Most species of polychaetes belong to the macrofauna together with animals from classes or subphylum like e.g. Bivalvia, Gastropoda and Crustacea. This study investigates the abundance and function of polychaetes in different ecosystems.

2.2 Purpose The purpose of this study is to investigate the ecological function of polychaeta by determining the species composition, the spatial distribution and the feeding habits of polychaete animals at some intertidal marine locations (rocky shores, sandy beaches and mangrove) in the area of Xiamen in south-eastern China. From this result we hope to be able to draw some conclusions about the ecological function of polychaetes in these environments.

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3 Theory

3.1 Polychaetes Polychaeta is a class within the phylum of annelida. They normally belong to the macrofauna in benthic environments since most polychaete species will not go through a 0.45 mm net. The animals’ body consists of segments and for most species, each segment has a pair of parapodia with bristles on it, hence the Latin name Polychaeta which means many bristles. There are now more than 10 000 species in the class of Polychaeta around the world living mainly in marine waters (Franzén, 2014). The class is very diverse with sizes ranging from about 1 mm to as long as 3 m. Most species are benthic but pelagic species occur as well (Fauchald & Rouse, Polychaete systematics: Past and present, 1997). Polychaetes can be found in extreme environments such as hydrothermal vents and at very large depths. Terrestrial species occur (Glasby & Fauchald, 2007). Most polychaetes have separate sexes and the females’ eggs and the males’ sperm are usually emitted to the sea water. Fertilized eggs are developed to larvae (trochophores) feeding on plankton before they evolve to worms at the sea bottom (Franzén, 2014). Other types of reproduction occur as well.

3.1.1 Basic Morphology Polychaetes are segmented worms and can be said to consist of three basic units: The presegmental region, the segmented trunk and the postsegmental region called pygidium (Rouse & Pleijel, 2001). Figure 2.1 shows the general appearance of polychaete animals. Focus in this text is on the head structure since this part is important for determining the feeding habits and thereby the ecological function of polychaetes. The morphology of polychaetes is diverse and the following description is generalized. The presegmental region is the part before the repeated segmented region in the anterior (front) end of the , and could also be called the head structure. The first part of the head is called prostomium and is connected to the peristomium. These two parts contains parts of the brain, sensory antenna, eyes, mouth, pharynx and palps. Some species has an elongated proboscis (mouth) that may be equipped with teeth and jaws. As can be seen in figure 2.1 the head structure is very diverse and can sometimes be used for identification of a species (Fauchald & Rouse, Polychaete systematics: Past and present, 1997). The presegmental region is important for determination of food type and feeding habits of the species. Developed eyes can often be seen on species that actively search their nutrition, like some carnivores. If teeth and jaws are present, the animal is probably omnivorous or carnivorous. If these structures are absent, the specimen is probably filter or deposit feeding. Filter feeding species often have tentacles to gather edible materials suspended in water. Deposit feeding species may have tentacles, but appendices from the head can also be completely absent. There is however exceptions from these typical head structures within all food types (Hutchings, 1998).

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The segmented trunk is commonly the largest part of the animal’s body and is built up from repeated segments. Each segment has (with a few exceptions) parapodia, used for locomotion and often also to circulate water and sediment in order to collect food. The features of the parapodia differs between species but can in most cases be divided into two rami, a dorsal notopodium and a ventral neuropodium on each side of the body. The structures of both rami vary from species to species. The parapodia carry bristles, also called chaeta, that are normally made of beta chitin (Rouse & Pleijel, 2001). The feature of the parapodia is also (together with the head structure) an important tool for the identification of polychaete species. Also the postsegmental region (pygidium) is diverse within the polychaetes. In some species, the pygidium only contains the anus, whereas other species has a more complex structure.

3.1.2 Feeding habits and Ecological Function The ecological function of polychaeta differs a lot between different species and they can be divided into several guilds or functional groups depending on nutrition habits (Glasby & Fauchald, 2007). What type of food a certain polychaete is feeding can be determined by looking at the morphology of the specimen (Fauchald & Rouse, Polychaete systematics: Past and present, 1997). Especially the head structure is of importance for determining the feeding habits. Many, but far from all, polychaetes are living in tubes made by sand, sticks or other available building material. Some spend all their life in the tubes, filtering water for food. These species often have a crown of long tentacles to collect food. Others leave the tubes to feed, either as carnivores or as deposit feeders by burrowing into the sediments. Polychaete deposit feeders (detritivores) eat fine, mainly dead organic material. Many of the deposit feeders make burrows in the sediments of marine waters and some species have long tentacles on the head for collecting nutrition to the mouth. The burrows made by polychaetes are beneficial for aerobic plankton and other animals living there due to the aeration of the sediments. The deposit feeders are decomposers and play an important role for the nutrient cycling (Hutchings, 1998). Carnivorous polychaetes often have a long proboscis that can be used to reach out to catch prey (Fauchald & Jumars, The Diet of Worms: A Study of Polychaete Feeding Guilds, 1979). They may also have teeth and jaws. Carnivores prey on other animals and is thus at a higher trophic level. Carnivorous polychaetes are generally somewhat larger compared to deposit and filter feeders and can be important food sources for fish and birds that have direct economic value for humans. Polychaetes are generally at a low trophic level and can be considered a base in marine food chains (Glasby & Fauchald, 2007). Since fish and other higher trophic levelled animals are important sources of food for humans all over the world, there should be an interest of understanding and protecting these food chains.

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Figure 2.1 The structure of polychaetes. (Left) Free-moving polychaetes, (A) Neanthes, (B) Nereis. (Right) Tube-dwelling (sedentary) polychaetes. (C) Amphitrite,(D) Sabella. (Encyclopædia Britannica Online, 1996)

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3.2 Sampling Locations Yundang lagoon is located in the city of Xiamen in south eastern China. The lagoon is a part of the Xiamen harbour and was for a long time subject to severe pollution. Since the 80’s, the lagoon has been part of a restoration program. As part of the restoration program, mangrove has been planted in the lagoon. Another measure is to get increased circulation of water to the inner lake (Chen, Lu, Hong, Ye, Wang, & Lu, 2010). Figure 2.2 shows the sampling spot for this study.

Figure 2.3 Sampling Location Yundang Lagoon. Xiatanwei is a relatively newly planted mangrove park situated in the intertidal zone of Tong’an bay in Xiamen. Huangcuo is a beach located at the sea side on Xiamen Central Island. Pictures from the sampling location can be seen in figure 2.4. Samples were taken in the intertidal area at low tide, both on the rocks (rocky shore) and in the sand sediments (sandy beach).

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Figure 2.2 Xiatanwei Mangrove Area.

Figure 2.4: Sampling area within the intertidal zone at Huangcuo beach. Left: Rocky shore. Right: Sandy beach.

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4 Method

4.1 Intertidal Zone On the sandy beach of Huangcuo, a 25*25 cm sample was dug to a depth of 30cm at three randomly chosen places in the intertidal area using a metal frame and a spade. The sample was placed in plastic bags. The samples were washed at the beach by first diluting with sea water in a bucket, mix the suspension to get the animals up to the free water and then filter the water/sand suspension through a 0.45 mm sieve. Since the sand was fine and easily went through the sieve, visible animals were collected directly from the sieve into a jar for further inspection in the lab. The procedure is shown in figure 3.1

Figure 3.1 Washing sample from sandy beach. Top left corner: Sampling from sandy beach. At the rocky shore at the Huangcuo beach, a 25*25 cm square was chosen randomly at three places at the intertidal part of a rock. In this spot, all animals were scraped off and collected in a jar and taken to the laboratory. The sample was put into formaldehyde solution and animals were identified and counted using a stereo microscope when necessary and wet weighted (species wise) using an electric scale. The procedure can be seen in figure 3.2.

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Figure 3.2: Left: Sampling on rocky shore. Right: Weighing identified species in the laboratory.

4.2 Mangrove Areas 3 sediment samples were collected from a mangrove area in Yundang Lagoon in central Xiamen. The samples were collected using a squared metal frame with the dimensions 25*25 cm and with a depth of 30 cm. The sample was sieved through a 0.45 mm sieve and the remaining material was collected in a plastic jar. In the laboratory, two of the samples were washed through a 0.45 mm sieve until the washing water was clear. The third sample was stained before washing for easier identification of living organisms. After washing, the samples were placed on a glass tray for counting. Parts of the remaining sample was placed on another glass dish and diluted with water. The material was carefully looked through using tweezers to find visible animals. The found animals were counted and identified using a stereo microscope and after that put into alcohol for preservation. 7 sediment samples were collected from Xiatanwei mangrove area in April (3 samples: F3-F5) and May (4 samples, G1-G4) 2014 with the same method as described above. These samples were prepared with alcohol and colorant to stain living animals in the sample for easier identification and separation. The samples were washed through a 0.45 mm sieve and the remains were combed for animals after diluting with water (figure 3.3).

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Figure 3.3 Left: Washing sample Right: Looking through samples for visible living organisms.

4.3 Food Types and Ecological Function The food type and thereby the ecological function of the different species were determined by looking in reference literature (Fauchald & Jumars, The Diet of Worms: A Study of Polychaete Feeding Guilds, 1979; Rouse & Pleijel, 2001) and by observing the head morphological structure. Mainly, the food type was based on which families certain species belong to.

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5 Results

5.1 Intertidal zone The sandy beach samples contained four different species in total, of which one species is polychaeta, Cirratulus cirratus. The polychaetes were only found in one of the three samples. List of all found macrofaunal species can be seen in table 4.1.

Table 4.1: List of species found at the sandy beach of Huangcuo. Number indicates number of individuals found in each sample and weight their total wet weight in grams.

Sample # 1 2 3 Class Species number weight (g) number weight (g) number weight (g) Bivalvia Lasaea undulata 1 0,0022 Crustacea 1 0,0007 7 0,0095 Gastropoda Nerita yoldii 1 0,0357 Poychaeta Cirratulus cirratus 2 0,0001

In the rocky shore samples, three species (belonging to two different families) of polychaetes were found: Perinereis cultifera, Perinereis camiguinoides and Syllis amica. A large part of the found individuals belong to either the barnacle species Amphibalanus Amphitrite or the bivalve Xenostrobus atrata. All found species are compiled and presented in table 4.2.

Table 4.2: List of species found at the rocky shore of Huangcuo. Number indicates number of individuals found in each sample and weight their total wet weight in grams.

Sample # 1 2 3 Class Species number weight(g) number weight(g) number weight(g) Bivalvia Crassostrea ariakensis 28 66,97 32 66,79 47 66,57 Bivalvia Xenostrobus atrata 36 2,2602 337 41,97 160 10,02 Bivalvia Lasaea undulata 2 0,004 27 0,0648 Crustacea Tylos granulatus 3 0,0331 1 0,0013 Crustacea Amphibalanus 42 19,0642 263 79,82 108 41,7 amphitrite Crustacea Nanosesarma minutum 3 0,137 2 0,1707 1 0,0445 Crustacea Corophium 2 0,0025 2 0,0035 triangulapedarum Gastropoda Cellana toreuma 22 0,3377 3 0,1135 Gastropoda Littoriaria articulate 65 2,2825 27 0,9553 41 1,5985 Gastropoda Littorina brevicula 7 0,0363 Insecta Chironumus sp. 2 0,0066 1 0,0039 Nemetinea Cerebratulina sp. 1 0,0032 Polychaeta Perinereis cultrifera 4 0,308 Polychaeta Perinereis camiguinoides 8 0,4008 1 0,0228 Polychaeta Syllis amica 6 0,0157 2 0,0016

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5.2 Mangrove Areas In the first two samples from the Yundang Lagoon, no animals were found. For easier identification, the third sample was coloured and 10 individuals of the polychaetes species Capitella capitata were found (figure 4.1). Capitella capitata is a nonspecific deposit feeder and are known to be an indicator of polluted areas and to be opportunistic (Rouse & Pleijel, 2001).

Figure 4.1 Capitella Capitata found in Yundang Lagoon. A total of 17 species of polychaeta were found in the samples from Xiatanwei. The species belong to nine different families. This means that this location has the greatest diversity of polychaetes among the locations of this study. The polychaete species found are indicated with Y in table 4.3. Apart from the polychaetes, a number of species from other classes were found, but are not reported in this text. The polychaetes made however a majority of the specimens.

5.3 Ecological Function A compilation of all found polychaete species can be seen in table 4.3. Y indicates that the species is present at the location. In table 4.4, probable food types of all found species of polychaetes are compiled. The food types have been estimated using reference literature as well as looking at the head structures of the animals. At the sandy beach of Huangcuo only one species of polychaete was found. Cirratulus cirratus is a deposit feeding worm known to be opportunistic and to live in areas enriched in organic compounds (Penry & Jumars, 1990). At the rocky shore of Huangcuo three species of polychaetes were found. One of these is probably filter feeding, one is omnivorous and one is carnivorous, eating mainly hydroids (small animals normally attached to the rocks). At the sandy beach of Huangcuo and in the Yundang lagoon, only one species of deposit feeding polychaetes were found. In Xiatanwei, a total of 17 polychaete species were found together with several species from other animal classes. Here several species of mainly deposit feeding and carnivorous polychaetes can be found.

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Table 4.3: Species distribution of polychaetes at different sampling locations. The first column contains the Chinese names of the species. Y indicates that the species is present.

Species Distribution of Polychaetes

Huangcuo Huangcuo Yundang Xiatanwei Species Beach Rocky Shore Lagoon 独齿围沙蚕 Perinereis cultifera Y Y 弯齿围沙蚕 Perinereis caiguinoides Y 粗毛裂虫 Syllis amica Y 丝鳃虫 Cirratulus cirratus Y 腺带 Neanthes glandicincta Y 奇异幼齿虫 Paraprionospio pinnata Y 马丁海锥虫 Spio martinensis Y Polydora cialata Y 小头虫 Capitella capitata Y Y 寡鳃 Nephtys digobranchia Y Mediomastus califoriensis Y 背蚓虫 Notomastus latericeud Y 叉毛矛毛虫 Phylo ornatus Y 长吻沙蚕 Glycera chirori Y 鳞腹沟虫 Scolelepis squamata Y 寡鳃齿吻沙蚕 Nephtys oligobranchia Y 刚鳃虫 Chaetozone setosa Y 细毛背鳞虫 Lepidonotus tenuisetosus Y 巧言虫 Eulalia viridis Y 拟特须虫 Paralacydonia paradox Y

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Table 4.4: Species and some of their head features and probable food type according to reference and morphology.

Food type and Ecological function of polychaete Species

Species Head morphological features Probable food type Perinereis cultifera jaws, cirri, antenna, 2 pair of eyes omnivorous Perinereis caiguinoides no visible jaws, antennae filter feeder Syllis amica palps, 2 pair of eyes carnivorous Cirratulus cirratus palps deposit feeder Neanthes glandicincta omnivorous or carnivorous Paraprionospio pinnata palps deposit feeder Spio martinensis palps deposit feeder Polydora cialata palps deposit feeder Capitella capitata No appendages deposit feeder Nephtys digobranchia carnivorous Mediomastus califoriensis belong to capitellidae deposit feeder Notomastus latericeud belong to capitellidae deposit feeder Phylo ornatus Less appendages deposit feeder Glycera chirori elongated proboscis possibly carnivore Scolelepis squamata deposit feeder Nephtys oligobranchia carnivorous Chaetozone setosa deposit feeder Lepidonotus tenuisetosus carnivorous Eulalia viridis Carnivorous/filter Paralacydonia paradox short antenna and palps no information

Figure 5.2 Left: Deposit feeding Spio martinensis Right: Carnivorous Glycera chirori Figure 4.2 show an example of a deposit feeding and a carnivorous polychaete. The food type can sometimes be seen by studying morphology of the head. The carnivorous Glycera chirori has an elongated proboscis to catch its prey whereas the deposit feeding Spio martinensis lack longer head appendices. The two specimens in figure 4.2 were found in Xiatanwei mangrove area.

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6 Discussion The sandy beach samples contained few animals, which makes it hard to draw any conclusions about the role of polychaetes at this location. The large difference between the three samples taken indicates that the biodiversity of the intertidal sandy beach is somewhat larger than what this study shows and that the sample size used may not be representative for a larger area. A greater number of samples collected at different times of the tidal cycle and at different times of the year would make the results more reliable. The one found polychaete species, Cirratulus cirratus, is probably a deposit feeding worm known to live in areas enriched in organic compounds (Penry & Jumars, 1990; Rouse & Pleijel, 2001). The rocky shore samples were all taken at low tide and most of the found species were attached to the rocks. At high tide, other animals like free-living carnivorous polychaetes may be found in larger amounts since they may follow the tide. Soft bottoms are known to have a larger biodiversity compared to hard substrata like rocky shores due to a larger variety of habitats and niches. The found polychaetes were omnivores, carnivores or filter feeders. The Perinereis species are used as fish bait and is a food source for fish and birds and is thus an important part of the food web of the area. The filter feeding animals (in this case perhaps other classes more than polychaeta) has a function of clarifying the water since they eat particles suspended in the water. The samples from Yundang Lagoon were smelly and full of plastics and other anthropogenic material. The water at the sampling location was probably badly circulated. It is possible that the two first samples we analysed contained macrofauna that we failed to find with our naked eye. The third sample was stained and was found to contain only Capitella capitata, which indicate that the macrofaunal diversity of the area is low. The ecological status of this area has been investigated before (Chen, Lu, Hong, Ye, Wang, & Lu, 2010; Olsson, 2012) and this small study indicate that the ecological status has not improved at the sampling location. No conclusions can be drawn about the status of the whole lagoon and more samples should have been taken at several locations in the lagoon to be able to draw conclusions. Capitella capitata, which was the only species of polychaeta found in the samples, is known as an indicator of polluted waters (Rouse & Pleijel, 2001). As a deposit feeder, the present polychaetes may be important to maintain a nutrient cycling and to aerate the sediments. In the Xiatanwei area eight samples were taken at two different occasions. This makes it hard to compare the results of the sampling with for instance the Yundang Lagoon sampling, where only three samples were taken at only one occasion. In the Xiatanwei samples, polychaetes of several kinds of food types were found. Even though other classes of macrofauna were found, a majority of the species were polychaetes. This suggests that polychaetes play an important role in this ecosystem. Mainly deposit feeders and carnivores were found here, meaning that the polychaetes function in the ecosystem is to recirculate nutrients and other materials in the sediments and to be a link in a larger food web.

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The method for finding the food types of each species can be improved to another study. The author’s knowledge of polychaete morphology is unfortunately limited and available literature not always unequivocal. These factors make the results presented in section 4.3 in this report not fully liable. For some species, like Paralacydonia paradox, no information seems to be available. For other species, information about the family is used even though several food types can be found among some families. Species in the family Nereidae (in this study: Perinereis cultifera, Perinereis caiguinoides and Neanthes glandicincta) seems to be carnivorous according to the head structure (teeth and jaws present) but studies show that some species in the family are actually grazing on algae or are opportunistic omnivores (Hutchings, 1998).

7 Conclusion A total of 20 species of polychaetes were found, belonging to 10 different families. A great majority of the species were found in the Xiatanwei mangrove area. The ecological function of polychaetes is, like the polychaetes themselves, very diverse. What function a certain species have in an ecosystem is dependent on the food type and on other species inhabiting the ecosystem. Since this study does not take all present species into account, it is hard to draw any conclusions about the ecological function of polychaetes in the sampling areas. Our results can however be used to get an idea of the situation at these locations and to study the morphology and food types of present species. To further investigate the ecological function of polychaetes, more samples must be taken at several occasions. Apart from studying the abundance of polychaete species, other classes of animals should be looked upon to be able to make a food web for the current location.

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8 Bibliography Chen, C., Lu, Y., Hong, J., Ye, M., Wang, Y., & Lu, H. (2010). Metal and metalloid contaminant availability in Yundang Lagoon sediments. Journal of Hazardous Materials(175), 1048– 1055. Encyclopædia Britannica Online. (1996). Amphitrite: physical structure. [Art]. Retrieved July 1, 2014, from Encyclopædia Britannica Online: http://www.britannica.com/EBchecked/media/389/The-structure-of-polychaetes Fauchald, K., & Jumars, P. A. (1979). The Diet of Worms: A Study of Polychaete Feeding Guilds. (M. Barnes, Ed.) Oceanogr. Mar. Biol. Ann. Rev ., 17, 193-284. Fauchald, K., & Rouse, G. (1997). Polychaete systematics: Past and present. Zoologica Scripta, 26, 71-138. Franzén, Å. (2014). Havsborstmaskar. Retrieved July 10, 2014, from Nationalencyklopedin: http://www.ne.se/lang/havsborstmaskar Glasby, C., & Fauchald, K. (2007, February 11). What are Polychaetes? Retrieved July 1, 2014, from POLiKEY, Australian Government: Department of the Environment, Water, Heritage and the Arts: http://www.environment.gov.au/biodiversity/abrs/online- resources/polikey/index.html#polychaetes Hutchings, P. (1998). Biodiversity and functioning of polychaetes. Biodiversity and Conservation, 7, 1133-1145. Olsson, S. (2012). Species diversity of macrobenthos. Xiamen: Lingfeng Summer Research School. Penry, D. L., & Jumars, P. A. (1990). Gut architecture, digestive constraints and feeding. Oecologia, 82, 1-11. Rouse, G. W., & Pleijel, F. (2001). Polychaetes. New York: Oxford University Press. Zhang, L. (n.d.). VVRF05 - International Summer Water Resources Research School. Retrieved July 4, 2014, from http://www.tvrl.lth.se/utbildning/courses/vvrf05/

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