Light Trap Hamburg 2015
Temporary Light Installation in the Port of Hamburg:
Examining the Impact of the Blue Port on Biodiversity
Nana Petzet, Bernd Reuter
Background and Concept
“Humans have always striven for light – the light bulb has made them the ruler over day and night.” (Laura Weissmüller, Süddeutsche Zeitung, 2014). The UNESCO had declared the year 2015 as the International Year of Light with the aim of “acknowledging the key role that light plays in science and culture”. However, a critical reflection on the adverse consequences of artificial lighting merely played a minor role in the UNESCO programme. That the night needs to be protected, to a certain extent, against the excessive use of artificial light sources in industrialized countries, was not addressed. And this despite the fact that relevant publications such as “Protection of the Night – Light Pollution, Biodiversity and Nocturnal Landscape”, released by the Federal Agency for Nature Conservation in 2013, have called for an altered awareness in the evaluation of light emission.
It was this largely neglected environmental problem of light pollution that was at the centre of our considerations, when Bernd Reuter and I met in Duvenstedt at his Peregrine Falcon Breeding and Research Station in the spring of 2014 to develop a project on art, ecology and environmental protection for Hamburg’s public space. Another theme-related inspiration was a description in the above publication of the phenomenon of behavioural change in animals effected by artificial illumination: “In studies for measuring the flight activity of insects near light sources, around thirteen to sixteen insect orders were counted. (…) Moths gather at the light sources in large numbers, but also other insects head for the light in masses, especially those that swarm only on a few days in summer. This can be clearly observed with dayflies, drifting above rivers in huge, cloud-like swarms, gathering near light sources on bridges and by the shores, flying around until, finally, they die beneath the luminaires. (…) Such behaviour of insects near light sources – beginning with a magical attraction and ending with the death of the animals – is called the “vacuum-cleaner effect”. Gerhard Eisenbeis, 2013)
1 May 2014, the station of the peregrine falcon breeding and research project in Hamburg Duvenstedt, photo: Nana Petzet
To further specify our topic, we decided to focus on illuminated advertising, as its use is more easily avoidable than that of functional lighting. In 2014 Hamburg’s city marketing once more promoted a large-scale light event in the port of Hamburg: Blue Port had been staged every other year since 2008, always during the high season of insect flight. We thus opted for using Blue Port as a case example for exploring the questions: which effects does artificial lighting that is temporarily employed for the purpose of advertising have on insect diversity? Are light pollution and the protection of darkness aspects that play a role in this context?
13 Feb 2014, brainstorming, Nana Petzet’s sketch book
Initially the idea emerged of an oversized circular insect trap based on blue fluorescent tubes. We applied for funding at the Hamburg Cultural Authority under the title Lichtfalle Hamburg (Light Trap Hamburg), and the art commission responsible for awarding project funding in the frame of the programme “Art in Public Space” decided on supporting our concept. We would thus be able to test the illuminants used by Michael Batz with regard to their capacity to attract insects, precisely one year after the Blue Port in 2014.
21 May 2014, the idea of the Light Trap as a luminous blue circle with an integrated screen, staged at favoured locations of Blue Port, Nana Petzet’s sketch book
Reference Blue Port 2014
On the occasion of the “Cruise Days”, the Hamburg-based light artist Michael Batz, once again, had installed 12,000 light sources – mostly blue fluorescent tubes – in the port area and the HafenCity. Over a period of five weeks, with the aid of 40 km of cables and a team of 40 assistants, they were mounted onto buildings, quay sections, cranes, jetties, pontoons, launches, ferries, tugboats, docks, operational vehicles, trees, bridges etc. This data corresponds approximately with those of the prior Blue Ports. In order to determine a relative percentage in the evaluation of the flight frequency of insects at an average Blue Port event, we compiled factors influencing the insect flight such as temperature, precipitation, wind and the moon phase for all Blue Ports that took place before our experiment.
2 Aug 2014, Blue Port No. 4 viewed from the site of Park Fiction, where the opening of Light Trap Hamburg took place one year later, photo: Nana Petzet
Weather and moon phases: Blue Port No. 1, 2, 3 and 4 were all staged in the period of the most intensive insect flight. In view of summerly temperatures and low precipitation – despite clouds obscuring the moon – the events offered favourable conditions for the attraction of insects through artificial lighting.
Once we learned in September 2014 that our application had been approved, we started to look for specialists with knowledge on night-active insects. In this regard, Jörg Roloff, who had died the year before, apparently had left a large gap in Hamburg. Yet there are various reasons for the diminishing knowledge of species. On the one hand, the universities are not training enough specialists in this field. On the other hand, there are less entomologically interested amateurs, the type of village teacher who collects bugs, as was quite common well into the 1960s. What also plays a role is children’s general lack of experiencing nature, the fact that collecting has gained a bad reputation as it includes killing animals, along with the rigid control of nature areas, especially concerning nature reserves.
Luckily, we could gain Martin Kubiak from the Center of Natural History (CeNak) at the University of Hamburg as a close cooperation partner. On 16 July 2015 he invited us to his office at the Entomology Department at the CeNak, where he gave us advice in matters such as the illuminated cloth and the proper conservation of the catch (ill. 9). At the CeNak, we also met with the certified biologist, Laura Marrano Palma, and Henry Tiemann, lecturer on zoology at the University of Hamburg, who agreed to coordinate the collection of voucher specimens and assist in the documentation of the experiment.
The extensive holdings of night-active butterflies assembled by the expert and collector Jörg Roloff was integrated into the collection of the Center of Natural History (CeNak). Photo: Helge Mundt
16 July 2015, the Light Trap Hamburg team, Nana Petzet, Bernd Reuter and Nina Kalenbach in consultation with Martin Kubiak at the Center of Natural History. Notes: documentary evidence, identification and numbers of species, butterfly net, ethyl acetate, 70% alcohol, genital structure, dissemination flights, times of main activity, reproduction. Photo: Helge Mundt
Construction of the Light Trap
The Light Source
The manufacturing company Philips describes the function of the illuminants with the product name TL-D Colored 36W Blue 1SL – the kind that is used for Blue Port events – is described as follows: “The coloured TL-D fluorescent lamps are suited for creating special colour effects. Fields of application include stage lighting, window display decoration, lighting at festivities, in bars or discos.” (Koninklijke Philips N.V., 2014)
In this context, we commissioned the Cologne-based astronomer Harald Bardenhagen, member of the Dark Sky Association and founder of the astronomy workshop “Sterne ohne Grenzen” (Stars Without Borders) to carry out a precise spectroscopic measurement of the kind of glow-discharge lamps used for the Blue Port events. The blue fluorescent tube OSRAM-LUMILUX-Blue-L36W-67 as tested on 16 June 2016 revealed: its light measured at the emission peak was clearly in the very short-wave range, towards UV light. The light colour lies within the spectrum of blue light and thus indicates a strong attractiveness for insects as found in light ranging from 350 to 550 nanometres.
The astronomer Harald Bardenhagen performing a spectroscopic measurement of the same glow-discharge lamps used during Blue Port in his workshop “Astronomie-Werkstatt Sterne ohne Grenzen”.
16 June 2016, tests of the spectrum of blue fluorescent tube OSRAM-LUMILUX-Blue-L36W-67 showed that the emission peak was clearly in the very short-wave range.
25 May 2015, 00:58 am: Preliminary testing at Nana Petzet’s studio at Saalehafen 49, Hamburg. Photo: Nana Petzet
We noted that insects were highly attracted by the blue light already during these first tests with coloured fluorescent tubes. Photo: Nana Petzet
The Light Trap – an octagonal “Blue Port dummy” fitted with sixteen blue fluorescent tubes of 150 cm each – was designed by Hans Georg Losekamm, owner of a company for advertising technology. Another important component of the trap is a white piece of cloth stretched behind the light source, inviting the attracted insects to settle on it; suitable pieces of cloth were tested in advance. The octagon itself measures 3,30 m in diameter; the total height of the trap including the base and hanging device for the material amounts to 4,80 m. The base consists of galvanized steel profiles with a tubular structure welded onto it, into which eight pavement slabs are laid as a stabilizing weight. The base structure is also conceived to hold an upright tube of galvanized steel adjustable in height and equipped with an anti-twisting device. This “mast” has a mounting flange at its upper end allowing it to hold the light fixture. The octagonal supporting structure for the light fixtures is made of screw-mountable aluminium square pipes. Eight fixtures are each equipped with two-light luminaires from both sides and protected against water through a transparent acrylic glass covering. The connected value amounts to 16 x 2 x 36 W, thus a total of ca. 1,200 W. Without the pavement slabs, the light trap weighs ca. 150 k. At the upper edge of the octagon, there is a beam and a mounting device for hanging the cloth.
Technical drawing of the light object, drawing: Hans-Georg Losekamm
As we intended to examine the entire port area with the Light Trap, we decided to install it on a boat. We were able to gain the members of an association maintaining the historical fireboat Repsold (known through the TV-series “Großstadtrevier”) for our project. The Repsold team offered to place both the boat and the crew at our disposal throughout the five-day action. The former fireboat once belonged to Hamburg‘s Fire Department, was built in 1941 at Hamburg-Finkenwerder and is 19 meters long and 4.10 meters wide. The light trap could be placed in a central position on the elevated deck – still bearing intact water pumps – and thus was well visible and easily accessible.
The light trap is constructed to allow its installation on rooftops of buildings. It can be disassembled in order to transport it through stairways and lifts. The roof area of the HafenCity University was a location we had temporarily considered as an operating site.
7 Aug 2015, installation of the trap on the Repsold in the boatyard Heuer in Finkenwerder. The owners of the historical fireboat Repsold not only allowed us to install the octagonal light trap on the boat, but the Repsold team collaborated with us during the entire five-day action. Photo: Helge Mundt
Course of Action
The opening event took place on 7 August 2015 on the viewing platform of Park Fiction at the Hafenstraße. Marie-Luise Tolle, deputy head official of the Cultural Authority gave a welcoming speech. Anke Haarmann, artist and philosopher from Hamburg, held the introductory lecture. She described the method of the artistic research project as an ironical citation: “Acting as a symbolic experimental set up, the blue light installation of Nana Petzet and Bernd Reuter cites the Blue Port created by the light designer Michael Batz on an aesthetical level. (…) The Light Trap’s ironic element is based on its aura of beauty – a beauty, which is at the same time a pitfall. What is fascinating is at once fatal. There thus exist two truths to the blue light installations – and irony is the art which questions the apparently one truth. The Light Trap visualizes the second, the more obscured truth of the blue light, by showing the insects that are led astray.”
When at the onset of dusk at 9 pm the Repsold equipped with the Light Trap first appeared in the port, one had a good view of it from the Park Fiction platform. There were about 500 visitors at the opening; including the guests on the five days of activity and random viewers and passers-by, one could assume a total of around 1000 visitors of the art action. We documented the entire course of action and published the images, films and texts on a project-based blog.
First appearance of the Light Trap in the port of Hamburg. Photo: Helge Mundt
Tours and Anchorage
On the weekend of 7 to 9 August, from dusk to about one o’clock at night, the Repsold with the four-metre-high light object cruised in the core area of the Blue Port in front of the Landungsbrücken and the HafenCity. We navigated on the northern branch of the Elbe between the Elbbrücken and Övelgönne, on the southern branch up to Köhlbrandbrücke and covered the following sections of the port (some repeatedly): Hansahafen, Baakenhafen, Vorhafen and Roßhafen. To be able to determine a relative percentage in the evaluation of the flight frequency of insects at an average Blue Port event, the Repsold with the Light Trap also anchored in the City Sportboothafen near Baumwall. This was meant to allow a systematic data collection with regard to fixed illuminants such as the Elbphilharmonie and port cranes.
We documented the entire action and results were uploaded to a blog, the address of which was advertised on a banner mounted on the Repsold. Photo: Helge Mundt
Navigation routes of the Repsold on 7, 8, and 9 August and anchorage on 10 and 11 August, charts: Marc Wiebach
8 Aug 2015, the research trip began. Photo: Helge Mundt
9 Aug 2015, the sign Lichtfalle drove off the sights of Hamburg harbor. Photo: Helge Mundt
9 Aug 2015, we drove the Norderelbe between Elbbrücken and Övelgönne. Photo: Helge Mundt
8 Aug 2015, mapping at the Köhlbrand, photo: Helge Mundt
The weather was quite favourable: warm, little rain, a little too much wind. Aside from various visitors and artist friends, there was always at least one insect specialist on board. From 7 to 9 August, this was the biologist Laura Marrano Palma, and on 8, 10 and 11 August, it was Henry Thiemann who supported the assessment procedures.
Weather and moon phases during the Light Trap’s tours from 7 to 12 August 2015.
Regarding the flight of insects, similar patterns could be observed on all five days, even if the climate conditions on 8 August were somewhat less favourable (colder and windier) than on 7 and 9 August. With increasing darkness, the Light Trap would become more attractive to insects: around 10 pm, more insects were attracted than at 9 pm. The flight of insects also increased when the boat reduced in speed. On the city side of the port, there were more insects than on the port side; positions near the land were clearly richer in insects than those distant from land. We could, for instance, always detect a notable increase when we landed near the Fischauktionshalle to take guests on board.
The visitors who came on board with us were also involved in the activities. Photo: Helge Mundt
15 Aug 2015: the trap on deck of the Repsold with guests, photo: Helge Mundt
Photo: Helge Mundt
On the second day, Laura Marrano Palma had brought a friend who is studying scientific illustration and helped collect the voucher specimens, here together with Glorian van Krimpen. Photo: Helge Mundt
Henry Tiemann, lecturer for zoology at the University of Hamburg, oversaw the collecting of voucher specimens and helped with the documentation of the first experiment. Photo: Helge Mundt
9 Aug 2015, a little greyhound attracted by the illuminants, photo: Helge Mundt
In sum, the results of our efforts in identifying the insect orders and assessing their numbers when the boat came to a halt, as on 9 August at midnight in Övelgönne and on 10 and 11 August when anchoring at the City Sportboothafen, could be described as follows: a massive flight of dipterous insects (Diptera), most evident in the presence of non-biting midges (Chironomidae), typical for port basins, whose larvae live in the mud of the Elbe. The suborder Nematocera stood out through a notable species diversity, reflected already in the animals’ mere difference in sizes. Crane flies (Tipulidae), on the contrary, were remarkably rare; only one individual was counted on 8 August. The presence of the suborder of flies (Brachycera) was marked by massive appearance and a considerable diversity. There were large and also very small flies, which would gather at the lower edge of the cloth once the boat had stopped for a while. More seldom were the caddisflies (Trichoptera), normally typical for the Elbe environment. We saw only a small number of them, ca. 15, in the City Sporthafen area, and kept three voucher specimens. There were only very few beetles (Coleoptera), one the first night and two on 10 August: the 19-spot ladybirds (Harmonia axyridis) accidentally introduced from China. The order of net-winged insects (Neuroptera) was meagerly represented by one green lacewing (Chrysopidae). We observed a single a water bug (Nepomorpha) on 9 August. On 11 August one chinch bug (Blissidae) and small wasp were attracted. In case of doubt, the midges, flies and other small insects were preserved in alcohol for later inspection. Only one specimen of each species was killed and pinned. Here, the list of butterflies:
7 Aug: 3 large yellow underwings (Noctua pronuba), 1 small owlet moth (Noctuidae)
8 Aug: 1 large yellow underwing (Noctua pronuba)
9 Aug: 1 snout moth (Pyralidae), 1 owlet moth (Noctuidae)
10 Aug: 2 small hawk moths (Sphingidae), 1 small white moth, 4 small butterflies
11 Aug: 1 silver Y moth (Autographa gamma)
Graphic: Marc Wiebach
The berthing place for the Light Trap at the Baumwall, photo: Helge Mundt
On 10 and 11 August a massive flight of dipterous insects could be observed. We observed, in particular, large numbers of chironomids (non-biting midges) typical for port basins, whose larvae live in the mud of the Elbe, photo: Helge Mundt
A mayfly (Ephemeroptera) and a caddisfly (Trichoptera), photo: Helge Mundt
A drawing by Henry Thiemann for explaining the attracted insect groups, photo: Helge Mundt
Here, an excerpt of Henry Tiemann’s on-site assessment in an interview on 10 August 2015:
Nana Petzet: It seems quite clear that there are a lot of insects present in the port area, also different species, and that they evidently are irritated by the blue fluorescent tubes. What conclusions could one draw on the fourth day of the experiment with Light Trap Hamburg?
Henry Tiemann: Here we can see how, if we use blue light or any bright light too lavishly, many insects are attracted by it, but then do not find the conditions of their natural habitat. They therefore will dry out on the walls of port basins or are not able find partners. One can also observe that, even in this relatively unfavourable urban situation, through the use of too much and the wrong light, many insects suffer damage. One must consider that 2015 generally has been a very bad year, for example for butterflies. One would normally expect to find several large yellow underwings and owlet moths. There are entire groups that I am missing. The geometer moths, the pyralid moths and also the tortrix moths, for instance, as these actually tend to appear in masses. But for a normal light-based attraction system, a light trap, there are very few different kinds of butterflies here, remarkably few.
In the Repsold cabin, Laura Marrano Palma prepared the samples, photo: Helge Mundt
The identification of the voucher specimens was overseen by entomologist Martin Kubiak and carried out at the Center for Natural History (CeNak) of the University of Hamburg. All voucher specimens, including those in the killing glass that had to be steeped before preparation, have now become part of the entomological collection of the CeNak.