Garden Pond Research Articles

Spread and status of seven submerged pest plants in New Zealand lakes

The distribution of seven submerged aquatic pest plants is reported. Lake vegetation surveys recorded pest plants in 27.9% of 344 lakes, with two species co‐occurring in 5.8%, and three species in 2.6% of lakes. Egeria densa was most frequent (15.4% of lakes), followed by Ceratophyllum demersum (9.0%), Lagarosiphon major (7.3%), and Utricularia gibba (5.5%). Spread since 2000 has continued for five pest plants, with 34 lakes invaded by U. gibba over 2004–08 alone. Early regional sites in proximity to human population centres were likely plant liberations and numerous potential founder colonies remain in garden ponds. Human activities were important for inter‐lake dispersal, with the exception of bird‐dispersed U. gibba. Significant lake associations between pest plants, and with presence of six exotic fish species, suggest common dispersal pathways and similar introduction risks. Therefore, predictions of future spread should be possible based on sources, dispersal pathways, and identifying key risk factors for lakes.

Dorset Palaeoeskimo Skin Processing at Phillip's Garden, Port au Choix, Northwestern Newfoundland

This paper examines artifactual and palaeo-limnological evidence of sealskin processing associated with Phillip’s Garden, a Dorset Palaeoeskimo site at Port au Choix in northwestern Newfoundland. We propose that harp seals were hunted from Phillip’s Garden as much for skins as for meat and fat, and that processing sealskins was the first step in the important activity of making clothes, boots, and other items. We outline the steps and tools involved in sealskin processing throughout the northern circumpolar world, and we identify specialized skin-processing tools in the Phillip’s Garden tool assemblage. Sealskin processing is also inferred from pollen and chironomid data from Bass Pond, adjacent to Phillip’s Garden. Disturbance across pollen taxa is evident at 2200– 1400 cal BP, and anomalous salinity values are evident at 2000–1400 cal BP. We argue that these are connected to Palaeoeskimo activities at the pond, in particular Dorset sealskin soaking and tanning. This study shifts our perception of Dorset activities at Phillip’s Garden away from a narrow focus on seal hunting and the site itself and broadens our view to include more of the multiplicity of day-to-day human activities that took place within a larger cultural landscape that included Phillip’s Garden and Bass Pond.

Small fish (Leucaspius delineatus) that are often released into garden ponds and amphibian breeding sites prey on eggs and tadpoles of the common frog (Rana temporaria)

Abstract Non-native fish often negatively affect amphibian populations. The sunbleak (Leucaspius delineatus), a small cyprinid fish, is often released into ponds that support amphibian populations because it is thought not to consume amphibian larvae; the argument was based on diet analyses. Here, we present results from a laboratory experiment that demonstrates that sunbleak consume amphibian eggs and larvae. Mortality of eggs and small tadpoles was 100%. Thus, sunbleak at least potentially could be harmful to amphibian populations despite their preference for small prey items reported in the literature. Although diet analyses are valuable, the assessment of whether a species is a predator of another should not be based solely on diet analyses. Experimental predation trials are necessary to assess predation risk.

Pumpkinseed sunfish (Lepomis gibbosus) invasions facilitated by introductions and nature management strongly reduce macroinvertebrate abundance in isolated water bodies

The pumpkinseed sunfish, Lepomis gibbosus, originates from Eastern North America and was introduced to the Netherlands in 1902 as an aquarium and garden pond fish. At present the pumpkinseed is widely spread throughout the Netherlands and occurs in a variety of aquatic habitats. It is especially abundant in moorland pools, fishing ponds and urban waters. Strong population development of the pumpkinseed appears to be facilitated by nature management practices in existing ponds (the removal of accumulated organic matter and macrophytes) and by creating new ponds. These measures enhance suitable breeding habitats that are free of competitors and predators. Isolated waters harbouring pumpkinseed were more often situated close to human habitation and infrastructure than could be expected based on the distribution of randomly selected isolated waters, identifying introductions as an important dispersal mechanism. In order to minimize the chances of introductions, planning of nature management practices should be done at distances over 250 m from human habitation and 100 m from infrastructure. Macroinvertebrate abundance in pools populated by pumpkinseed was eighty three percent lower than in pools without pumpkinseed, probably due to opportunistic feeding and high pumpkinseed abundances. Currently there is little experience with pumpkinseed control. However, options to be explored include: decreasing depth of colonized waters by filling them with soil allowing them to occasionally dry up, introducing native competitors and predators and the use of biodegradable piscicides. In addition, limitation of the sale of pumpkinseed is required as well as public education on the consequences of introducing exotic species.

Propagule pressure and the invasion risks of non‐native freshwater fishes: a case study in England

European countries in general, and England in particular, have a long history of introducing non‐native fish species, but there exist no detailed studies of the introduction pathways and propagules pressure for any European country. Using the nine regions of England as a preliminary case study, the potential relationship between the occurrence in the wild of non‐native freshwater fishes (from a recent audit of non‐native species) and the intensity (i.e. propagule pressure) and diversity of fish imports was investigated. The main pathways of introduction were via imports of fishes for ornamental use (e.g. aquaria and garden ponds) and sport fishing, with no reported or suspected cases of ballast water or hull fouling introductions. The recorded occurrence of non‐native fishes in the wild was found to be related to the time (number of years) since the decade of introduction. A shift in the establishment rate, however, was observed in the 1970s after which the ratio of established‐to‐introduced species declined. The number of established non‐native fish species observed in the wild was found to increase significantly (P < 0·05) with increasing import intensity (log10x + 1 of the numbers of fish imported for the years 2000–2004) and with increasing consignment diversity (log10x + 1 of the numbers of consignment types imported for the years 2000–2004). The implications for policy and management are discussed.

Palatial Garden Pond of the Early Shang

Palatial Garden Pond of the Early Shang

Palatial Garden Pond at the Shang City in Yanshi, Henan

Palatial Garden Pond at the Shang City in Yanshi, Henan

Hydrocotyle ranunculoides

<i>Hydrocotyle ranunculoides</i>

長野市松代町東部に残る湧水と水路の現状と特徴

Matsushiro in Nagano city is known as the castle town where the watercourses and garden ponds realised originally in Edo era remain. Especially at the south of town, Nagano City designated 4 streets as the Traditional Environment Preservation Area. But at the east of town, it remains too the watercourses, garden ponds and water springs. And their present conditions are not known. This study aims to clear their present conditions and their characteristics in comparison with the present conditions of 4 streets of the south of town and the castle town map made at the end of 18th century. As a result, it clears the points as follows. The sources of water are only water springs, and there exist 21 springs. The distinction of watercourses which we can recognise at the Traditional Environment Preservation Area is not clear. There are a few garden watercourses which are characteristics at Matsushiro. But water springs and watercourses drawn on the map of 18th century are almost found in the present conditions. In conclusion, these water springs and watercourses, even if some garden water courses were lost, they have the historical value, and it is considered that they deserve to be preserved.

The first record of Misgurnus anguillicaudatus in Germany

Oriental weatherfish Misgurnus anguillicaudatus, from southern China, have been imported to Germany in large numbers for the garden pond trade. The first record of M. anguillicaudatus from Central Europe, a population that has been established for at least 14 years in a small nature reserve in Germany, is detailed.

長野市松代町の城下町絵図に見られる水路システムの特徴

Matsushiro, castle town build in Edo era (1600-1867), is known by the water courses systems which flow from the pond of garden to garden pond of neighbor in the town. They are called Garden Water Courses. In Matsushiro, there are about 10 plans of this castle town drawn in Edo era. And, on the 4 of them, the watercourses systems are described. This study aims to clear the formation and the characteristics of these watercourses systems and their classification. As a result, on the 4 plans, probably drawn in the 18 century, the water courses are marked in all town area, except one quarter, Tonomachi. And as the town area spread, the number of springs was increased, and the watercourses were extended. In another kind of plan in this era, called Watercourses plan, the watercourses system at Tonomachi is described in detail, included the Garden watercourses. Consequently, the watercourses system became clear throughout Matsushiro. And the classification of watercourses needs to be reconsidered.

Biological warfare in the garden pond: tadpoles suppress the growth of mosquito larvae

Abstract. 1. Although tadpoles and mosquito larvae may compete for scarce resources in natural freshwater systems, the mechanisms involved in such competition remain largely unstudied.2. Replicated artificial ponds were set up to examine the role of pathogenic interference (water‐borne growth inhibitors) in two tadpole–mosquito systems from south‐eastern Australia. One system comprised taxa that are commonly sympatric in freshwater ponds (tadpoles of Limnodynastes peronii and larvae of Culex quinquefasciatus) while the other comprised species that co‐occur in brackish water ponds (tadpoles of Crinia signifera and larvae of Ochlerotatus australis).3. Water that had previously contained tadpoles suppressed the rates of survival and pupation of mosquito larvae in both systems. Fungicide reduced or eliminated this effect, suggesting that the growth inhibitors may be fungal organisms (possibly the yeast Rhodotorula glutinis) from tadpole faeces. Fungicide also enhanced growth rates of tadpoles.4. These results suggest that interference competition between tadpoles and mosquito larvae is mediated by other organisms in some ecological systems.

野生魚類の生息環境としての園池

In Kyoto City, there are many garden ponds which have water supplied by canal from Lake Biwa. Various kinds of fish, including endangered species which have colonized from the lake, inhabit these garden ponds, and fish variety is rich in some of them. The purpose of this study is to clarify the environmental variables affecting the species richness of fish in the limited space of garden ponds which have the same water source. Analyses using TWINSPAN and CCA have revealed that the diversity of micro-habitat has a very important role in species richness which depends on the establishment of symbiotic relations in garden ponds. Existence of a stream and/or a high turnover rate of water were found to contribute to the diversity of micro-habitats in garden ponds. These results could contribute to the planning and design of ponds as wildlife habitats.

The study and characterization of Emperor Traiano's Villa (Altopiani di Arcinazzo, Roma) using high‐resolution integrated geophysical surveys

AbstractIn this work, the results of high‐resolution integrated geophysical surveys of the archaeological site of Traiano's Villa (Altopiani di Arcinazzo, Roma, Italy) are presented. The Villa of Roman Emperor Marco Ulpio Traino (AD 98–117) was built in Arcinazzo (Italy), approximately 55 km northeast of Rome. Today, the only remains left standing at the site are the public building entrances comprising a small portion of the entire site. Over 5 ha, adjacent to the entrance remains, had not been surveyed. As part of an ongoing study to rescue this national archaeological treasure, high‐resolution ground‐penetrating radar (GPR) surveys, using a submetre profile spacing, integrated with a gradiometric survey, were conducted. Amplitude GPR time‐slice analysis indicates that many structural foundations and walls of the villa are still well preserved below the surface. Time‐slices below 1.5 m in one area indicate two large mushroom shaped structures enclosed within a large building over 100 m in length. These structures are believed to be dipping pools within a larger structure believed to be the bathhouse to the villa. At the location west of the bathhouse a large oval shaped anomaly 45 m along its major axis was located. This subsurface structure is believed to be an oval garden pond or a swimming pool. Several other remnants of rectangular buildings coincident with the oval structure but much deeper were also imaged. Other structures include a long rectangular corridor that contains many square shaped rooms, which has been interpreted as a criptoporticus.The magnetic map, related to part of the area investigated, shows many dipole anomalies. These anomalies represent linear and semicircular structures of the villa. The magnetic results provide complementary information to the GPR survey that lines out walls and floors. Copyright © 2003 John Wiley &amp; Sons, Ltd.

The number of children drowning in garden ponds is increasing

The number of children drowning in garden ponds is increasing

Preventing deaths by drowning in children in the United Kingdom: have we made progress in 10 years? Population based incidence study

Detailed information on drowning in children is not routinely collected by offices of national statistics. Few studies have been carried out in the United Kingdom, and none has been done...

The Formation Process of Water System Connecting Garden Ponds in Edo Period and its Use in Castle Town Matsushiro (Tonomachi District)

長野市松代町は城下町であり, 水道網が発達していた。武家屋敷において庭園の水を隣家から隣家へと流す泉水路が存在し, 現在でも一部ながら残されている。江戸時代における泉水路の形成過程, その範囲, その用途を明らかにするのが本研究の目的である。対象地は上級武家屋敷地であった殿町とした。真田家文書などの水道絵図から分析すると, 次の結論が得られた。中水道が江戸時代中期頃に形成され始め, 後期には泉水路として水系を形成する。殿町にはほとんどの家に泉水路が流れ主に生活用水として, 後期には部分的には養魚池の給水源としても用いられていた。その範囲はおそらく松代城下町全体に及んだのではないかと推測される。

Evidence for the induction of interference competition between anuran larvae in plastic pond cages

AbstractWe recently showed that growth inhibition of Bufo bufo larvae by those of Rana temporaria in garden ponds only occurred when the larvae were confined in plastic cages. We therefore carried out further experiments to investigate the mechanism of this growth inhibition. Bufo bufo larvae were raised in mesh cages, plastic cages or plastic cages with supplementary food either alone or in the presence of R. temporaria. Three lines of evidence suggested that competition in the plastic cages had an interference component: firstly, growth inhibition of B. bufo by R. temporaria was only seen in plastic cages despite the fact that these cages supported normal growth rates of B. bufo in the absence of R. temporaria; secondly, food supplementation in plastic cages did not reduce the extent of B. bufo growth inhibition; and thirdly Anurofeca (= Prototheca) richardsi production was high in plastic cages but not in other treatments and correlated negatively with subsequent B. bufo larval growth. Plastic cages supported a different trophic web from other treatments and biotic factors seem the most likely regulators of A. richardsi abundance in these pools.

中国の同泰寺の園池について

本稿は, 日本の浄土庭園の園池と同様な配置をとる園池の中国における最も古い例の一つとして, 同泰寺の園池を紹介するものである。同泰寺は, 6世紀前半, 南朝の帝都建康 (今日の南京) に創建された当時を代表する寺院で, そこには敦煙の壁画に見られるような構成配置をとる建築と園池があったようである。

No Evidence for Kin-Preferential Swarming in a Daphnia magna Population Coexisting with Fish

In a recent paper, Young et al. (1994) proposed a graphical model indicating that under certain conditions (a dome-shaped functional response of the predator) prey swarming may entail not only benefits for the individual (Hamilton 1971), but also for the swarm as a whole (group level benefit). They argue that, in organisms that partially reproduce by apomictic parthenogenesis such as Daphnia, any grouprelated benefits may favour the formation of swarms among clone-mates. Young et al. (1994) then present field and laboratory observations on D. longispina that support the above notion, by showing that electrophoretically defined uniclonal populations often show a higher cohesion than multiclonal assemblages in a laboratory set-up, and that a swarm of D. longispina in a garden pond apparently mainly consisted of members of a single 'electrophoretic clone' (sensu Carvalho & Crisp 1987). The authors themselves point to the fact that this latter result needs to be interpreted with caution due to the fact that only one enzyme system (esterase), with an uncertain number of loci, was screened. We here present data that show for a population that coexists with fishes, where swarming is most probably a predator-avoidance strategy, that Daphnia swarms are no less genetically diverse than non-swarming individuals. The present data were collected during a survey of spatial genetic heterogeneity in Daphnia magna Straus populations, and in our opinion provide a more robust test of the above hypothesis than that presented by Young et al. (1994), since more samples (individuals and swarms/non-swarms) were analysed at four loci per individual. Our findings do not support the generality of kin-preferential swarming behaviour in Daphnia as a predator avoidance response.