The Techniques For Sampling Micro Organisms Environmental Sciences Essay

Macroinvertebrates are the most normally used group of beings in the biomonitoring of watercourses and rivers worldwide ( Metcalfe-Smith, 1996 ; cited in Friberg et al. , 2006 ) . Therefore, the sampling of macroinvertebrates is an established construct in which many different techniques have been developed ( peculiarly within rivers and watercourses ) . The purpose of my research is to construct upon current literature and arguments which intend to happen the most effectual manner of trying macroinvertebrate communities in pool ecosystems. Although there is no widely accepted method of trying macroinvertebrates in such environments, methods with rigorous guidelines, such as the National Ponds Survey method ( Biggs et al. , 1998 ) have been constructed to let consequences to be collaborated and compared. Alternate methods, with differing trying attempts besides feature widely in the literature such as: expanse gauze, kick-sampling ( Bradley and Ormerod, 2001 ) , horizontal and perpendicular activity traps ( Muscha et al. 2001 ) , the Gerking box sampling station ( Gerking 1957 ; cited in Gates et al. 1987 ) , the grab sampling station and the corer ( Hyv & A ; ouml ; nen and Nummi, 2000 ) . Some appraising research has assessed efficaciousness of trying methods ( for illustration, Brinkman and Duffy, 1996 and Garc & A ; iacute ; a-Criado and Trigal, 2005 ) , nevertheless, there is a deficiency of research that compares more differing techniques. It could be argued that pools are hard to try, in comparing to fluxing rivers and watercourses, as methodological jobs frequently arise, particularly in the diverse littoral zone ( Wetzel, 1990 ; cited in Hyv & A ; ouml ; nen and Nummi, 2000 ) . In add-on, an mean pool contains assorted different mesohabitats which each support differing beings. Therefore, more sampling is needed when stand foring a whole pool ecosystem.

Hire a custom writer who has experience.
It's time for you to submit amazing papers!

order now

Literature Review

Harmonizing to Hortal et Al. ( 2006 ) , species profusion is the most normally used biodiversity index for preservation, ecological research and macroecology. Therefore, it is of import that trying techniques are every bit effectual as possible to stand for species profusion. Sampling methods purpose to truly stand for the diverseness and the copiousness of beings of a certain country. An effectual method is one which achieves this, with minimum trying attempt.

Although pools potentially have high macroinvertebrate diverseness, research has historically focussed on larger organic structures of H2O such as lakes, rivers or watercourses ( Jurado et al. 2008 ) . Therefore, trying techniques are by and large better developed for these types of environments ( presently, over 50 different attacks exist [ Friberg et Al. 2006 ] ) , as compared with pools. In add-on, many pools are extremely vegetated or less accessible and hence these methods designed for rivers or watercourses are frequently impractical.

Quantitative attacks ( e.g. Surber sampling station, catch sampling station ) focal point on trying to stand for the full community of, for illustration, a set country. Quantitative research ( by and large ) aims to understate prejudice with controls and consequences in numerical informations sets which can be statistically compared. Qualitative attacks ( e.g. sweep gauze, kick-sampling ) , on the other manus, are more subjective and frequently give a more overall representation, for illustration, alternatively of utilizing a fixed country, samples are frequently taken from a much larger country. There are many methods, of both types, that are widely used and accepted as effectual.

Kick-sampling is widely used as a standard method ( normally in watercourses and rivers ) of qualitatively trying macroinvertebrates ( Bradley and Ormerod, 2002 ) . The method does non necessitate specialist equipment and is comparatively cheap ( Storey et al. 1991 ) . It focuses on perturbation of the watercourse bed in order to rinse macroinvertebrates downstream and ( normally ) into a ‘D-net ‘ . Bradley and Ormerod ( 2002 ) concluded in their probe that kick trying provides dependable and consistent samples which are able to stand for differences in gatherings between differing sites at different times. However, they besides suggest that kick-sampling is non an efficient step of rare taxa. This method would non be practical in standing Waterss, nevertheless, as there is usually small flow to rinse animate beings into a net.

In contrast, a quantitative method that is widely used in fluxing Waterss is the Surber sampling station ( Surber, 1937 ; cited in Wu and Legg, 2009 ) ( Figure 1 ) , as assessed in Storey et Al ‘s ( 1991 ) work. The Surber sampling station is made from a metal frame and an affiliated cyberspace which is placed on the watercourse bed in order to surround the sampling country. Similarly to the kick-sample, this set country is so disturbed rinsing animate beings downstream and into the net. However, unlike kick-sampling, the Surber sampling station by and large collects fewer persons and more taxa ( Storey et al. , 1991 ) and is hence better in the aggregation of rare taxa. In add-on, this method provides representation of a fixed country, which frequently makes informations more easy comparable.

Figure 1: Surber sampling station

Integrated Land Management Bureau

( )

Obviously, some methods are more effectual at mensurating copiousness, whilst others are more effectual at maximizing taxa. Likewise, some methods under-estimate certain systematic groups, whilst others over-estimate. Often, utilizing an original attack ( inspired by these normally used techniques ) , along with an appropriate sampling attempt, outputs desired informations ( for illustration, the ‘National Ponds Survey Method ‘ [ Biggs, et al. , 1998 ] ) . In fact, Hampton and Friedenberg ‘s ( 2002 ) unrelated methodological probe suggests that utilizing a combination of methods increases the truth of a community study by averaging method-specific sampling prejudices. The choice of a method should besides see issues that consequence the quantitative or qualitative characteristics of a technique.

Jurado et Al. ( 2008 ) used two different methods to asses the biodiversity of to a great extent vegetated wetlands in their appraising paper. Concentrating on gauze ( qualitative attack ) and two-types of horizontal activity traps ( semi-quantitative attack ) ( Figure 2 ) , their consequences showed that a combination of both schemes will give a more complete appraisal of taxon profusion. In fact, Jurado et Al. ( 2008 ) suggest that each technique is more effectual for different taxa ( for illustration: activity traps are much more effectual for the gaining control of top marauders in macroinvertebrate communities than sweep gauze ) .

Figure 2: An illustration activity trap design ( a: position into funnel, B: sidelong position )

Minnesota Pollution Control Agency: Macroinvertebrate Community Sampling Protocol for Depressional Wetland and Monitoring Sites.

( )

Furthermore, Muscha et Al. ‘s ( 2001 ) paper interestingly focuses entirely on activity traps, but evaluates two different types. Horizontally and vertically deployed traps were used, and the consequences compared. Again, different taxa were sampled more efficaciously by both of the methods, nevertheless overall the vertically deployed traps captured a greater species richness and copiousness. Muscha et Al. ( 2001 ) describes perpendicular traps to hold outperformed horizontally deployed traps and hence, are the preferable method.

As in all illustrations of trying methods, it is of import to see the importance of mesohabitats ; for illustration, Hose et Al. ( 2004 ; cited in Clarke et al. , 2006 ) focused their survey on the certain pools and ripples of a watercourse. Community assemblages vary mostly over little distances in watercourses ( Beisel et al. , 1998 ) , as they do in pools. It is hence of import that these mesohabitats are represented every bit efficaciously as possible with chosen methods.

Throughout this survey, Biggs et Al. ‘s ( 1998 ) paper: A usher to the methods of the National Ponds Survey ( and other instructional documents ) will be on a regular basis referred to. This is so that the guidelines of the method can be followed. The basic thought follows a qualitative method of sweep gauze. However, a peculiar sampling attempt which considers the mesohabitats of the pool is applied, which attempts to standardize the information.

The National Ponds Survey method was foremost developed in 1989, and was updated and modified for many old ages ( Biggs et al. , 1998 ) . The monitoring web was ab initio developed in order to asses the quality and proctor long term tendencies of the biodiversity within the UK ‘s pools ( Pond Conservation, 2010 ) . Pond Conservation ( 2010 ) province that one of the purposes of the study is to advance the usage of standardized study techniques. This illustrates the importance of holding a standard method, which would let different surveies to be reasonably compared.

The purpose of my probe is to asses the efficaciousness of the National Ponds Survey method ( qualitative attack ) , in visible radiation of two alternate methods: Horizontally deployed activity traps ( semi-quantitative ) and a fixed country method ( quantitative ) .

My hypotheses are that the National Ponds Survey method will try the highest copiousness degrees, whilst the activity traps will try more species, particularly the more rare taxa. However, I anticipate that the fixed country method will necessitate the least sum of trying attempt. Therefore, my expected result is that a combination of methods would be the most effectual in trying macroinvertebrate communities in pools.

The Method

In order to stand for a scope of techniques, three methods will be used in the survey: a qualitative, a semi-quantitative and a quantitative method. Concentrating around the National Ponds Survey ( NPS ) , the other two contrasting methods that will be used are activity traps and a fixed country sacking method. Although some surveies have involved activity traps ( for illustration Hyv & A ; ouml ; nen and Nummi, 2000 ) , the method is non widely used and understood. Although Muscha et Al. ( 2001 ) concluded that vertically deployed traps were more effectual than horizontally deployed 1s, this survey will concentrate on horizontal traps. This is to understate complications in the design and building of the method. Alongside, will be a fixed country method which aims to quantitatively insulate a certain transect of the pool, which will so be sampled with a net.

The locations to be sampled are both within the environing urban landscape of Birmingham. Exact sites are yet to be decided nevertheless, the physical belongingss, such as the size and the deepness of the pools will be similar ( effort to keep invariables ) . Using preliminary work, one site will be a general higher diverseness ( less polluted ) site than the other. This is aims to place a possible nexus between a method ‘s effectivity and the general diverseness of a pool ( for illustration, to see if one method works more efficaciously at a lower diverseness site than at a higher diverseness site ) .

The NPS and fixed country methods will be carried out five times at each of two locations. The activity traps will be left down for 24 hours ( as featured in the literature [ for illustration Bataille and Baldassarre, 1993 ] ) . The methods will be carried out in the same clip frame, but trying to understate any perturbation effects between trying.

Method inside informations:

Method One: The National Ponds Survey Method

This entails following the guidelines as laid out by the study ( Biggs et al. 1998 ) . Although guidelines province that the pool needs to be surveyed in three different seasons, this will be impractical for this survey and besides unneeded, as the survey focuses on the technique itself. In an initial appraisal of the pool, the normal field observations are to be taken ( including pH, temp, conduction etc ) and the chief mesohabitats are identified ( as guided in Biggs et al. , 1998 ) . A three minute trying clip is so every bit divided between these mesohabitats. These mesohabitats are netted smartly for the allocated period of clip, seeking to avoid deep accretions of soft deposit. A farther one minute is spent seeking for beings that may be missed by the three-minute expanse, for illustration: under rocks and logs and across the H2O surface ( these beings are added to the chief sample ) . These samples are observed and so returned to the research lab: if samples can non by sorted on return from the field they are to be preserved in industrial methylated spirit ( IMS ) .

Method Two: Horizontally deployed activity traps

This involves building a series of indistinguishable activity traps and puting them at changing locations and at changing deepnesss. The trap design will be to a great extent influenced by those featured in figure 2, antecedently. However, on each joggle, there will be three traps, secured at different highs. Two of these ( six traps wholly ) will be secured into the bed in each mesohabitat ( as assessed in method one ) , which jointly give one sample. After being left undisturbed for 24 hours ( Bataille and Baldassarre, 1993 ) , the samples will be emptied out of the traps and filtered through a standard screen. Similarly to the NPS method, samples are observed and so taken back to the research lab: if samples can non by sorted on return from the field they are to be preserved in IMS.

Method Three: Quantitative attack – sectioning pail

The 3rd method involves utilizing a standard 80 liter capacity ashcan ( for easiness and convenience ) , with both terminals free to insulate a subdivision ( transect ) of the pool. Once the ashcan has been placed, the bed is smartly disturbed for 30 seconds and so the country is to a great extent netted for the undermentioned 60 seconds. This is done in changing deepnesss ( shallow, mid and deepest possible ) of each mesohabitat three times – once more, jointly one sample. Like both other methods, the samples are observed and so taken back to the research lab: if samples can non by sorted on return from the field they are to be preserved in IMS.

Potential Problems

Complications in the field ( for illustration: equipment failure, utmost conditions conditions, accidents etc. )

Problems with the methods ( for illustration: obvious effects of perturbation, practical issues eg: traps excessively large/too little etc. )

Not being able to finish the lab work ( excessively many samples/samples excessively big )

Problems analyzing the information ( eg: package accessibility/reliability, storage of informations etc )

The Analysiss

My informations purposes to demo that different macroinvertebrate trying methods reveal different things about the same aquatic community. Therefore, the informations should relatively demo each methods ‘ strengths and failings.

Initially, the three informations sets from each method at site one are to be compared, whilst the three informations sets from each method at site two are to be compared, individually. The information from each method is so to be compared between the sites ( for illustration, method one/site one is to be compared with method one/site two ) .

There are a figure of ways in which to compare the information. Similar methodological surveies show many different statistical comparing methods. Mann Whitney U-test is used in Connor et Al. ‘s ( 2004 ) work to compare the findings of pond-net and box trying methods. However, Hyv & A ; ouml ; nen and Nummi ( 2000 ) use a Spearman rank correlativity to compare the comparative copiousness of taxa between the methods used. Whilst Jurado et Al. ( 2008 ) use an ANOVA to happen differences between the taxon profusion between methods, along with t-tests to compare the informations from two types of activity traps. The information from the three methods will be statistically compared, utilizing SPSS statistical package, through one of these standard comparing techniques.

To reason, the purpose of my research is to construct upon current literature and arguments which intend to happen the most effectual manner of trying macroinvertebrate communities in pool ecosystems. I expect to happen that each method has its advantages along with disadvantages, and the most effectual manner to try macroinvertebrates would be to utilize a combination of techniques. This survey ( along with other methodological comparings ) is of import in footings of the direction of UK pools. By holding an accurate image of the biodiversity of our pools, preservation and direction schemes can be put in topographic point consequently in order to forestall possible diverseness loss.


I'm Heather

Would you like to get such a paper? How about receiving a customized one?

Check it out