Select until 25 January

Totals Castricum aan Zee (zeetrek) 2017 - 2026

	Species	2017	2018	2019	2020	2021	2022	2023	2024	2025	2026	Totals	Average	Present	Year Maximum
1.	Dark-bellied Brent Goose	4620	5160	5710	6496	6195	1457	4421	3209	3912	1	41181	4118	1	6496 (2020)
2.	Pale-bellied Brent Goose	2	0	0	13	2	0	0	7	1	0	25	2.5	0	13 (2020)
3.	Black Brant	0	0	0	1	0	0	0	0	0	0	1	0.1	0	1 (2020)
4.	Canada Goose	33	7	16	7	39	27	27	1	43	0	200	20	0	43 (2025)
5.	Barnacle Goose	1133	3858	3162	3097	2122	1107	781	1786	6129	235	23410	2341	0	6129 (2025)
6.	Bar-headed Goose	0	0	2	0	0	0	0	0	0	0	2	0.2	0	2 (2019)
7.	Ross's Goose	0	0	0	2	0	0	0	0	0	0	2	0.2	0	2 (2020)
8.	Snow Goose	0	1	0	0	0	0	0	0	0	0	1	0.1	0	1 (2018)
9.	Greylag Goose	231	161	137	284	220	335	120	251	658	2	2399	240	23	658 (2025)
10.	Anser sp.	0	0	0	0	70	0	2	0	0	0	72	7.2	0	70 (2021)
11.	goose sp.	520	98	450	119	137	540	17	27	2	0	1910	191	0	540 (2022)
12.	Domestic Goose	7	0	1	2	0	1	2	0	0	0	13	1.3	0	7 (2017)
13.	Pink-footed Goose	4	74	51	585	5	112	0	1042	397	0	2270	227	0	1042 (2024)
14.	Tundra Bean Goose	0	12	1	51	0	210	0	5	3	0	282	28	0	210 (2022)
15.	Bean Goose sp.	0	0	4	0	0	0	0	0	0	0	4	0.4	0	4 (2019)
16.	Eurasian White-fronted Goose	42	89	8	146	889	111	53	0	148	0	1486	149	0	889 (2021)
17.	Black Swan	0	0	0	0	0	1	0	0	0	0	1	0.1	0	1 (2022)
18.	Mute Swan	20	26	12	26	17	4	4	9	22	0	140	14	0	26 (2018)
19.	Bewick's Swan	0	0	0	0	0	1	0	0	0	0	1	0.1	0	1 (2022)
20.	swan sp.	3	0	0	0	0	0	0	0	0	0	3	0.3	0	3 (2017)
21.	Egyptian Goose	95	49	108	145	109	128	86	49	222	8	999	100	0	222 (2025)
22.	Shelduck	1190	1701	1014	1138	1964	1173	1361	919	1648	10	12118	1212	6	1964 (2021)
23.	Ruddy Shelduck	0	0	0	0	0	0	13	0	0	0	13	1.3	0	13 (2023)
24.	Garganey	30	17	16	29	35	119	2	2	19	0	269	27	0	119 (2022)
25.	Shoveler	1077	564	1064	2531	459	1202	156	280	1837	0	9170	917	19	2531 (2020)
26.	Gadwall	152	94	143	124	123	70	56	56	124	4	946	95	9	152 (2017)
27.	Wigeon	5144	2988	2127	4370	4643	1789	2937	1315	2585	5	27903	2790	519	5144 (2017)
28.	Mallard	34	72	26	18	24	25	16	10	9	0	234	23	1	72 (2018)
29.	Pintail	855	238	129	185	324	494	104	149	177	0	2655	266	0	855 (2017)
30.	Teal	3139	1988	1931	1747	2294	2135	1020	881	3560	23	18718	1872	51	3560 (2025)
31.	duck sp.	7	42	7	263	78	5	1	6	35	0	444	44	3	263 (2020)
32.	Red-crested Pochard	1	0	4	0	0	0	0	0	0	0	5	0.5	0	4 (2019)
33.	Pochard	20	18	13	122	25	31	7	20	8	16	280	28	0	122 (2020)
34.	Tufted Duck	66	137	80	103	169	103	49	33	66	0	806	81	0	169 (2021)
35.	Scaup	77	38	16	401	77	53	19	28	19	0	728	73	0	401 (2020)
36.	Aythya sp.	0	20	0	0	5	0	0	0	1	0	26	2.6	0	20 (2018)
37.	King Eider	0	0	0	0	0	0	0	1	0	0	1	0.1	0	1 (2024)
38.	Eider	593	415	438	853	797	507	429	340	860	3	5235	524	27	860 (2025)
39.	Velvet Scoter	221	83	121	268	418	258	316	1366	58	1	3110	311	17	1366 (2024)
40.	Common Scoter	24735	16642	10858	64026	49809	18531	21650	64199	13441	298	284189	28419	11747	64199 (2024)
41.	Long-tailed Duck	11	7	5	0	8	6	1	3	0	0	41	4.1	1	11 (2017)
42.	Goldeneye	23	19	3	35	38	53	9	9	18	4	211	21	0	53 (2022)
43.	Smew	0	2	0	0	13	1	1	0	9	0	26	2.6	0	13 (2021)
44.	Goosander	4	10	8	11	16	14	10	3	12	2	90	9	0	16 (2021)
45.	Red-breasted Merganser	428	439	553	588	619	678	211	137	491	11	4155	416	6	678 (2022)
46.	Swift	68	0	13	2	0	2	4	7	8	0	104	10	0	68 (2017)
47.	Feral Pigeon	43	22	9	8	1	3	0	0	0	0	86	8.6	0	43 (2017)
48.	Stock Dove	0	0	2	0	0	0	0	1	0	0	3	0.3	0	2 (2019)
49.	Red-necked Grebe	4	6	6	5	7	13	3	5	4	1	54	5.4	3	13 (2022)
50.	Great Crested Grebe	465	1324	571	344	927	1764	377	460	483	55	6770	677	1912	1764 (2022)
	Species	2017	2018	2019	2020	2021	2022	2023	2024	2025	2026	Totals	Average	Present	Year Maximum
51.	Slavonian Grebe	2	5	0	1	0	0	1	1	0	0	10	1	3	5 (2018)
52.	Black-necked Grebe	1	2	0	1	1	0	0	1	1	0	7	0.7	1	2 (2018)
53.	Black-necked / Slavonian Grebe	0	0	0	0	1	2	0	0	2	0	5	0.5	1	2 (2022)
54.	Greater Flamingo	0	0	0	0	0	0	0	0	3	0	3	0.3	0	3 (2025)
55.	Oystercatcher	453	614	542	580	626	315	492	239	942	0	4803	480	11	942 (2025)
56.	Avocet	73	146	98	63	165	336	17	79	457	0	1434	143	0	457 (2025)
57.	Grey Plover	418	222	603	803	606	683	392	323	1109	0	5159	516	4	1109 (2025)
58.	Golden Plover	87	16	27	8	35	29	24	1	27	0	254	25	0	87 (2017)
59.	Dotterel	0	0	0	0	0	0	0	0	1	0	1	0.1	0	1 (2025)
60.	Ringed Plover	237	185	133	122	48	70	316	158	394	0	1663	166	3	394 (2025)
61.	Little Ringed Plover	1	1	0	2	1	2	0	2	2	0	11	1.1	0	2 (2020)
62.	Lapwing	3	224	30	1	205	874	0	0	0	0	1337	134	0	874 (2022)
63.	Kentish Plover	1	0	1	0	1	0	2	1	2	0	8	0.8	0	2 (2023)
64.	Whimbrel	400	98	430	891	708	256	109	108	375	0	3375	338	0	891 (2020)
65.	Curlew	120	196	231	158	347	251	81	60	117	0	1561	156	0	347 (2021)
66.	Bar-tailed Godwit	2110	137	558	4538	4212	6263	80	4479	955	0	23332	2333	12	6263 (2022)
67.	Black-tailed Godwit	1	18	5	1	1	1	0	0	5	0	32	3.2	0	18 (2018)
68.	Woodcock	1	1	0	1	3	0	0	0	0	0	6	0.6	0	3 (2021)
69.	Snipe	5	21	8	18	3	33	9	3	9	0	109	11	0	33 (2022)
70.	Grey Phalarope	1	1	0	1	0	1	5	1	0	0	10	1	0	5 (2023)
71.	Common Sandpiper	0	5	3	3	5	1	5	1	6	0	29	2.9	0	6 (2025)
72.	Green Sandpiper	4	2	4	2	0	4	0	1	2	0	19	1.9	0	4 (2017)
73.	Wood Sandpiper	1	0	0	0	2	1	1	0	0	0	5	0.5	0	2 (2021)
74.	Redshank	62	111	117	342	94	147	63	108	196	0	1240	124	0	342 (2020)
75.	Spotted Redshank	1	0	12	1	3	16	0	1	6	0	40	4	0	16 (2022)
76.	Greenshank	15	9	23	8	18	16	1	5	50	0	145	15	0	50 (2025)
77.	Turnstone	36	21	66	69	84	77	111	17	95	0	576	58	1	111 (2023)
78.	Knot	360	527	391	2351	686	1295	208	334	2666	0	8818	882	0	2666 (2025)
79.	Ruff	33	50	126	26	0	41	6	4	26	0	312	31	0	126 (2019)
80.	wader sp.	635	29	396	115	220	33	10	26	77	0	1541	154	0	635 (2017)
81.	small wader	0	0	0	0	0	0	0	0	6	0	6	0.6	0	6 (2025)
82.	large wader	0	0	0	0	56	868	0	0	0	0	924	92	0	868 (2022)
83.	Curlew Sandpiper	17	6	5	8	8	3	2	3	4	0	56	5.6	0	17 (2017)
84.	Temminck's Stint	0	1	0	0	0	0	0	0	1	0	2	0.2	0	1 (2018)
85.	Sanderling	2741	1172	1544	4437	1893	900	1827	980	1714	0	17208	1721	516	4437 (2020)
86.	Dunlin	2132	1654	2275	2684	4391	6191	4814	763	7332	4	32240	3224	6	7332 (2025)
87.	Purple Sandpiper	5	0	0	5	1	0	4	5	2	0	22	2.2	0	5 (2017)
88.	Little Stint	8	2	2	4	1	4	11	2	3	0	37	3.7	0	11 (2023)
89.	Calidris sp.	624	115	38	215	163	99	51	84	175	0	1564	156	0	624 (2017)
90.	Little Tern	184	107	298	486	461	342	56	84	351	0	2369	237	0	486 (2020)
91.	Gull-billed Tern	0	2	0	1	1	0	0	0	2	0	6	0.6	0	2 (2018)
92.	Caspian Tern	2	0	1	3	2	0	5	0	2	0	15	1.5	0	5 (2023)
93.	Whiskered Tern	0	0	0	0	0	0	0	1	0	0	1	0.1	0	1 (2024)
94.	Black Tern	321	99	353	857	2408	260	495	258	342	0	5393	539	6	2408 (2021)
95.	White-winged Black Tern	0	0	0	0	7	0	1	1	2	0	11	1.1	0	7 (2021)
96.	Arctic Tern	199	248	138	166	279	487	55	237	111	0	1920	192	0	487 (2022)
97.	Common/Arctic Tern	5272	2153	7508	15598	34566	8455	12991	12406	18027	0	116976	11698	204	34566 (2021)
98.	Common Tern	3100	2627	4106	6094	5956	4866	6827	2170	1501	0	37247	3725	395	6827 (2023)
99.	Roseate Tern	0	0	0	1	0	0	0	0	0	0	1	0.1	0	1 (2020)
100.	sterna sp.	0	0	0	0	0	0	0	6	0	0	6	0.6	0	6 (2024)
	Species	2017	2018	2019	2020	2021	2022	2023	2024	2025	2026	Totals	Average	Present	Year Maximum
101.	Sandwich Tern	11840	13461	10855	14618	27851	6282	7088	4580	11137	0	107712	10771	291	27851 (2021)
102.	Little Gull	16727	989	13790	10427	41392	6242	6719	870	7243	2	104401	10440	2117	41392 (2021)
103.	Kittiwake	4237	2404	888	7369	2058	2162	4525	1000	194	133	24970	2497	2057	7369 (2020)
104.	Sabine's Gull	3	1	0	1	0	0	3	2	0	0	10	1	0	3 (2017)
105.	Black-headed Gull	13158	6197	19710	17222	25755	22676	6915	10569	10175	41	132418	13242	765	25755 (2021)
106.	Laughing Gull	0	0	1	0	0	0	0	0	0	0	1	0.1	0	1 (2019)
107.	Mediterranean Gull	44	35	98	65	234	44	44	43	68	0	675	68	4	234 (2021)
108.	Common Gull	8865	5304	11267	16592	17354	14818	11876	5282	9534	282	101174	10117	1820	17354 (2021)
109.	Caspian Gull	3	6	4	4	9	13	17	4	9	0	69	6.9	1	17 (2023)
110.	Herring Gull	1	0	0	0	0	0	1	0	6	0	8	0.8	0	6 (2025)
111.	L. argentatus x L. hyperboreus	0	0	0	0	1	0	0	0	0	0	1	0.1	0	1 (2021)
112.	Yellow-legged Gull	3	2	1	2	6	5	2	0	5	0	26	2.6	2	6 (2021)
113.	Great Black-backed Gull	437	5	4	16	32	51	26	37	54	0	662	66	24	437 (2017)
114.	Glaucous Gull	0	0	0	0	0	0	1	0	0	0	1	0.1	0	1 (2023)
115.	Lesser Black-backed Gull	164	26	39	71	242	63	26	8	327	0	966	97	7	327 (2025)
116.	Laridae sp.	0	0	0	0	0	0	1	0	0	0	1	0.1	0	1 (2023)
117.	Iceland Gull	2	0	2	0	1	0	0	1	0	0	6	0.6	0	2 (2017)
118.	Long-tailed Skua	3	0	0	5	3	5	8	3	3	0	30	3	3	8 (2023)
119.	skua sp.	22	16	15	13	31	12	19	4	15	0	147	15	3	31 (2021)
120.	Arctic Skua	78	52	61	47	400	89	213	22	74	0	1036	104	7	400 (2021)
121.	S. parasiticus / pomarinus	0	0	3	0	1	0	5	0	0	0	9	0.9	0	5 (2023)
122.	Pomarine Skua	16	13	39	12	10	5	5	0	7	0	107	11	1	39 (2019)
123.	Great Skua	48	28	15	17	33	0	10	1	8	0	160	16	3	48 (2017)
124.	Puffin	1	0	1	3	2	3	2	0	0	0	12	1.2	0	3 (2020)
125.	Black Guillemot	0	0	1	0	0	0	0	0	0	0	1	0.1	0	1 (2019)
126.	Razorbill	28	34	21	42	19	51	183	11	5	8	402	40	21	183 (2023)
127.	Razorbill/Guillemot	2009	3963	2072	7701	3694	3877	3422	1185	214	563	28700	2870	221	7701 (2020)
128.	alca / fratercula spec	0	0	0	0	0	0	0	0	1	0	1	0.1	0	1 (2025)
129.	Little Auk	2	0	0	3	3	12	0	5	1	0	26	2.6	1	12 (2022)
130.	Guillemot	232	45	205	120	237	109	106	78	8	1	1141	114	70	237 (2021)
131.	Red-throated Diver	410	901	519	542	974	2785	1590	504	405	0	8630	863	322	2785 (2022)
132.	Black-throated Diver	27	7	9	26	52	19	7	15	5	1	168	17	1	52 (2021)
133.	Great Northern Diver	2	0	1	1	1	2	3	2	0	0	12	1.2	1	3 (2023)
134.	diver sp.	3041	3156	1736	5440	7275	3449	2665	2449	2439	737	32387	3239	767	7275 (2021)
135.	Great Northern/Yellow-billed Diver	0	1	0	0	1	0	0	0	0	0	2	0.2	0	1 (2018)
136.	Storm Petrel	2	0	0	0	0	0	0	0	0	0	2	0.2	0	2 (2017)
137.	storm-petrel sp.	1	0	0	0	0	0	0	0	0	0	1	0.1	0	1 (2017)
138.	Leach's Petrel	5	27	0	4	5	2	4	1	2	0	50	5	0	27 (2018)
139.	Fulmar	11	6	4	8	56	6	2	21	5	11	130	13	0	56 (2021)
140.	Sooty Shearwater	9	9	1	10	25	75	35	9	48	0	221	22	0	75 (2022)
141.	Manx Shearwater	5	17	3	0	1	3	6	1	32	0	68	6.8	0	32 (2025)
142.	Balearic Shearwater	0	0	0	0	0	4	1	0	0	0	5	0.5	0	4 (2022)
143.	Gannet	939	1759	516	1280	2005	987	4399	1814	2889	254	16842	1684	282	4399 (2023)
144.	Cormorant	450	226	0	527	10346	1111	346	1603	9677	0	24286	2429	212	10346 (2021)
145.	Spoonbill	88	2	21	52	327	5	138	46	44	0	723	72	0	327 (2021)
146.	Little Egret	2	2	0	1	0	0	1	0	2	0	8	0.8	0	2 (2017)
147.	Great White Egret	1	2	2	7	4	19	2	9	4	0	50	5	0	19 (2022)
148.	Grey Heron	6	11	27	27	12	11	21	11	23	0	149	15	0	27 (2019)
149.	Purple Heron	0	0	0	2	0	0	0	0	0	0	2	0.2	0	2 (2020)
150.	Osprey	2	0	1	1	0	3	0	0	2	0	9	0.9	0	3 (2022)
	Species	2017	2018	2019	2020	2021	2022	2023	2024	2025	2026	Totals	Average	Present	Year Maximum
151.	Sparrowhawk	2	1	0	3	2	0	1	2	0	0	11	1.1	0	3 (2020)
152.	Marsh Harrier	0	2	5	2	2	0	1	0	0	0	12	1.2	0	5 (2019)
153.	Hen Harrier	1	1	1	1	1	2	0	1	0	0	8	0.8	0	2 (2022)
154.	White-tailed Eagle	0	0	0	0	0	1	0	0	0	0	1	0.1	0	1 (2022)
155.	Rough-legged Buzzard	0	0	0	0	0	0	0	1	0	0	1	0.1	0	1 (2024)
156.	Common Buzzard	1	0	0	0	0	0	0	0	0	0	1	0.1	0	1 (2017)
157.	Short-eared Owl	1	0	1	0	0	0	0	0	0	0	2	0.2	0	1 (2017)
158.	Kestrel	7	3	0	3	0	0	2	0	4	0	19	1.9	0	7 (2017)
159.	Merlin	5	4	6	3	0	2	0	0	3	0	23	2.3	0	6 (2019)
160.	Hobby	1	0	1	1	0	0	0	0	0	0	3	0.3	0	1 (2017)
161.	Peregrine	4	4	4	4	3	1	5	2	0	0	27	2.7	0	5 (2023)
162.	Rose-ringed Parakeet	1	0	0	0	0	0	0	0	0	0	1	0.1	0	1 (2017)
163.	Jackdaw	6	0	0	3	0	0	0	0	0	0	9	0.9	0	6 (2017)
164.	Rook	2	1	1	0	3	3	2	0	2	0	14	1.4	0	3 (2021)
165.	Carrion Crow	0	0	0	0	0	0	0	0	1	0	1	0.1	0	1 (2025)
166.	Blue Tit	3	0	0	0	0	0	0	0	0	0	3	0.3	0	3 (2017)
167.	Skylark	695	0	21	0	13	3	71	2	7	0	812	81	0	695 (2017)
168.	Shore Lark	4	0	0	0	0	8	10	0	2	0	24	2.4	0	10 (2023)
169.	Sand Martin	7	3	15	1	0	0	0	0	18	0	44	4.4	0	18 (2025)
170.	Swallow	41	2	15	20	0	7	2	4	39	0	130	13	0	41 (2017)
171.	House Martin	0	0	4	0	0	0	0	2	1	0	7	0.7	0	4 (2019)
172.	Zitting Cisticola	0	0	0	0	0	0	1	0	0	0	1	0.1	0	1 (2023)
173.	Starling	168	0	4	73	468	349	3811	41	4506	0	9420	942	0	4506 (2025)
174.	Fieldfare	0	710	0	0	0	0	0	0	0	0	710	71	0	710 (2018)
175.	House Sparrow	0	0	0	0	0	2	0	0	0	0	2	0.2	0	2 (2022)
176.	Blue-headed Wagtail	0	0	3	0	5	0	0	1	6	0	15	1.5	0	6 (2025)
177.	Yellow Wagtail (flavissima)	0	0	0	1	0	0	0	0	1	0	2	0.2	0	1 (2020)
178.	Grey-headed Wagtail	0	1	0	1	0	0	0	2	0	0	4	0.4	0	2 (2024)
179.	Yellow wagtail sp.	9	2	0	0	1	0	0	0	5	0	17	1.7	0	9 (2017)
180.	Grey Wagtail	4	5	0	1	1	0	12	0	13	0	36	3.6	0	13 (2025)
181.	White Wagtail	0	2	25	1	10	3	0	5	0	0	46	4.6	0	25 (2019)
182.	alba wagtail sp.	53	18	7	9	16	2	1	1	12	0	119	12	0	53 (2017)
183.	Pied Wagtail	1	0	0	0	0	0	0	0	2	0	3	0.3	0	2 (2025)
184.	Meadow Pipit	2	0	0	1	0	0	2	0	3	0	8	0.8	0	3 (2025)
185.	Tree Pipit	1	2	0	0	1	0	0	0	0	0	4	0.4	0	2 (2018)
186.	Water Pipit	0	0	0	0	0	0	0	0	2	0	2	0.2	0	2 (2025)
187.	Rock Pipit	3	1	2	1	4	1	0	1	5	0	18	1.8	0	5 (2025)
188.	Chaffinch	0	0	0	0	0	0	10	0	0	0	10	1	0	10 (2023)
189.	Brambling	1	0	1	0	0	0	0	0	0	0	2	0.2	0	1 (2017)
190.	Common Rosefinch	0	1	0	0	0	0	0	0	0	0	1	0.1	0	1 (2018)
191.	Twite	0	2	0	0	0	0	0	0	0	0	2	0.2	0	2 (2018)
192.	Linnet	3	0	0	1	0	0	0	0	0	0	4	0.4	0	3 (2017)
193.	Mealy Redpoll	4	81	0	0	0	0	0	0	0	0	85	8.5	0	81 (2018)
194.	Lesser Redpoll	0	0	0	0	0	0	0	0	1	0	1	0.1	0	1 (2025)
195.	Redpoll	2	0	0	0	0	0	0	0	0	0	2	0.2	0	2 (2017)
196.	Serin	0	0	1	0	0	0	0	0	0	0	1	0.1	0	1 (2019)
197.	Siskin	2	0	0	1	0	0	0	0	1	0	4	0.4	0	2 (2017)
198.	Lapland Bunting	0	0	1	1	0	0	0	0	0	0	2	0.2	0	1 (2019)
199.	Snow Bunting	7	4	4	1	6	10	5	1	5	0	43	4.3	0	10 (2022)
200.	Yellowhammer	0	0	0	0	0	0	0	0	1	0	1	0.1	0	1 (2025)
	Species	2017	2018	2019	2020	2021	2022	2023	2024	2025	2026	Totals	Average	Present	Year Maximum
201.	Reed Bunting	8	0	0	0	0	0	0	0	0	0	8	0.8	1	8 (2017)
	Other species
1.	Harbour Porpoise	82	78	44	83	227	57	52	55	26	0	704	70	17	227 (2021)
2.	Humpback whale	0	0	0	0	0	0	0	1	0	0	1	0.1	0	1 (2024)
3.	Grey seal	3	3	1	1	5	2	1	0	0	0	16	1.6	1	5 (2021)
4.	Common Seal	11	9	3	6	14	5	1	1	4	0	54	5.4	6	14 (2021)
5.	Common / Grey seal	0	0	2	3	0	0	1	0	0	0	6	0.6	0	3 (2020)
	Other species
1.	Brimstone	0	0	1	0	0	0	0	0	0	0	1	0.1	0	1 (2019)
2.	European Peacock	0	0	1	0	0	0	0	0	0	0	1	0.1	0	1 (2019)
3.	white sp. (butterfly)	3	7	11	9	1	1	0	0	0	0	32	3.2	0	11 (2019)
4.	Red Admiral	0	0	5	0	0	0	0	0	0	0	5	0.5	0	5 (2019)
5.	Painted Lady	0	0	2	0	0	0	0	0	0	0	2	0.2	0	2 (2019)
	Species	2017	2018	2019	2020	2021	2022	2023	2024	2025	2026	Totals	Average	Present	Year Maximum
	Totals	128835	86902	111015	211323	272181	131744	117765	129882	133444	2716	1325807	132581	24536
	Observation hours	279:45	208:14	246:10	300:06	324:30	220:06	226:59	166:30	246:50	4:30	2,223:40	222:22

Trektellen

Totals Castricum aan Zee (zeetrek) 2017 - 2026